Workplace interventions for smoking cessation

  • Review
  • Intervention

Authors


Abstract

Background

The workplace has potential as a setting through which large groups of people can be reached to encourage smoking cessation.

Objectives

1. To categorize workplace interventions for smoking cessation tested in controlled studies and to determine the extent to which they help workers to stop smoking.
2. To collect and evaluate data on costs and cost effectiveness associated with workplace interventions.

Search methods

We searched the Cochrane Tobacco Addiction Group Specialized Register (July 2013), MEDLINE (1966 - July 2013), EMBASE (1985 - June 2013), and PsycINFO (to June 2013), amongst others. We searched abstracts from international conferences on tobacco and the bibliographies of identified studies and reviews for additional references.

Selection criteria

We selected interventions conducted in the workplace to promote smoking cessation. We included only randomized and quasi-randomized controlled trials allocating individuals, workplaces, or companies to intervention or control conditions.

Data collection and analysis

One author extracted information relating to the characteristics and content of all kinds of interventions, participants, outcomes and methods of the studies, and a second author checked them. For this update we have conducted meta-analyses of the main interventions, using the generic inverse variance method to generate odds ratios and 95% confidence intervals.

Main results

We include 57 studies (61 comparisons) in this updated review. We found 31 studies of workplace interventions aimed at individual workers, covering group therapy, individual counselling, self-help materials, nicotine replacement therapy, and social support, and 30 studies testing interventions applied to the workplace as a whole, i.e. environmental cues, incentives, and comprehensive programmes. The trials were generally of moderate to high quality, with results that were consistent with those found in other settings. Group therapy programmes (odds ratio (OR) for cessation 1.71, 95% confidence interval (CI) 1.05 to 2.80; eight trials, 1309 participants), individual counselling (OR 1.96, 95% CI 1.51 to 2.54; eight trials, 3516 participants), pharmacotherapies (OR 1.98, 95% CI 1.26 to 3.11; five trials, 1092 participants), and multiple intervention programmes aimed mainly or solely at smoking cessation (OR 1.55, 95% CI 1.13 to 2.13; six trials, 5018 participants) all increased cessation rates in comparison to no treatment or minimal intervention controls. Self-help materials were less effective (OR 1.16, 95% CI 0.74 to 1.82; six trials, 1906 participants), and two relapse prevention programmes (484 participants) did not help to sustain long-term abstinence. Incentives did not appear to improve the odds of quitting, apart from one study which found a sustained positive benefit. There was a lack of evidence that comprehensive programmes targeting multiple risk factors reduced the prevalence of smoking.

Authors' conclusions

1. We found strong evidence that some interventions directed towards individual smokers increase the likelihood of quitting smoking. These include individual and group counselling, pharmacological treatment to overcome nicotine addiction, and multiple interventions targeting smoking cessation as the primary or only outcome. All these interventions show similar effects whether offered in the workplace or elsewhere. Self-help interventions and social support are less effective. Although people taking up these interventions are more likely to stop, the absolute numbers who quit are low.

2. We failed to detect an effect of comprehensive programmes targeting multiple risk factors in reducing the prevalence of smoking, although this finding was not based on meta-analysed data.

3. There was limited evidence that participation in programmes can be increased by competitions and incentives organized by the employer, although one trial demonstrated a sustained effect of financial rewards for attending a smoking cessation course and for long-term quitting. Further research is needed to establish which components of this trial contributed to the improvement in success rates.

4. Further research would be valuable in low-income and developing countries, where high rates of smoking prevail and smoke-free legislation is not widely accepted or enforced.

摘要

工作场所干预是否有益于戒烟

研究背景

工作场所有潜力作为鼓励群体戒烟的有利环境。

研究目的

1,将对照研究中的工作场所戒烟干预进行分类,并确定这些干预对帮助工作人员戒烟或控烟的有效程度。
2,对工作场所干预措施的花销和成本效应进行数据收集与分析。

检索策略

我们检索了Cochrane Tobacco Addiction Group Specialized Register(截至2013年7月)、 MEDLINE (1966–2013年7月)、EMBASE (1966–2013 年7月) 和PsycINFO (截至2013年7月)等 数据库中。 还检索了关于烟草问题的国际会议摘要,并追溯了纳入研究和相关综述的参考文献。

标准/纳入排除标准

选择在工作场所实施的戒烟干预措施研究。只纳入随机或半随机对照试验,分组对象为个体、工作场所或公司。

数据收集与分析

由一名评价者提取数据,另一名评价者进行核查。提取的信息包括所有干预措施的特点及内容、研究对象、结局指标和研究方法。这次更新,我们对主要干预进行了Meta分析,运用一般反向方差法生成OR值和95%的可信区间。

主要结果

本次更新综述共纳入了57项研究(61项比较)。其中31项对工作场所干预的研究是针对个体员工的,措施包括群体治疗、个别辅导、自助手册、尼古丁替代疗法及社会支持,还有30项以整体的工作场所作为研究干预,包括环境因素、激励措施和综合项目。这些试验通常是中等或高等级别的证据,跟其他环境下的干预结果是一致的。群体治疗(RR=1.71,95%CI=1.05 - 2.80,8项试验,包括1309位受试者),个别辅导(OR=1.96,95%CI=1.51 - 2.54,8项试验,包括3516位受试者),药物疗法(OR=1.98,95%CI=1.26 - 3.11,5项试验,包括1092位受试者)),还有主要针对或单独珍贵戒烟的多项干预措施(OR=1.55,95%CI=1.13 - 2.13,6项试验包括5018位受试者),跟空白对照组或小干预组相比,以上所有治疗措施都提高了戒烟率。自助手册效果较差(OR=1.16,95%CI=0.74 - 1.82,6项试验,包括1906位受试者),还有2项预防复发的干预试验(包括483位受试者)对长期禁烟无效。综合性针对多风险因素的干预措施的控烟效果缺乏足够证据。

作者结论

1,有较强的证据支持针对个体吸烟者的干预措施能增加戒烟的可能性,具体措施包括个体与群体咨询辅导和克服尼古丁依赖的药物治疗。无论是在工作场所或是其他地方,这些干预措施均有相似的效果。自助式干预和社会支持的效果较差,尽管接受干预者的戒烟可能性更高,但实际戒烟成功的人数仍然很少。

2,没有证据表明综合性针对多风险因素的干预措施对提高戒烟率有效,尽管这项研究不是建立在meta分析的基础上。

3,有限证据表明,由雇主或领导组织的竞赛和奖励刺激能促员工的参与度,尽管一项试验证实了参与戒烟项目对长期戒烟的金钱奖励。这项试验需要更多的研究增加成功率。

4,需要对低收入国家和发展中国家做进一步研究,因为高吸烟率和无烟立法在这样的国家没有被广泛接受或加强实施。

翻译注解

更新译者:严毓倩、王莹,审校:王莹。北京中医药大学循证医学中心。2017年5月30日

Résumé scientifique

Interventions sur le lieu de travail pour le sevrage tabagique

Contexte

Le lieu de travail offre des possibilités en tant que cadre permettant de toucher des groupes importants afin d'encourager le sevrage tabagique.

Objectifs

1. Classer les interventions de sevrage tabagique sur le lieu de travail testées dans des études contrôlées et déterminer dans quelle mesure celles-ci aident les travailleurs à arrêter de fumer.
2. Recueillir et évaluer des données sur les coûts et la rentabilité des interventions sur le lieu de travail.

Stratégie de recherche documentaire

Nous avons effectué des recherches dans le registre spécialisé du groupe Cochrane sur le tabagisme (juillet 2013), MEDLINE (de 1966 à juillet 2013), EMBASE (de 1985 à juin 2013), et PsycINFO (jusqu'à juin 2013), entre autres. Nous avons consulté des résumés de conférences internationales sur le tabac et les bibliographies des études et revues identifiées afin de trouver des références supplémentaires.

Critères de sélection

Nous avons sélectionné les interventions réalisées sur le lieu de travail pour promouvoir le sevrage tabagique. Nous n'avons inclus que les essais contrôlés randomisés et quasi randomisés assignant des individus, des lieux de travail ou des entreprises aux groupes d'intervention ou témoins.

Recueil et analyse des données

Un auteur a extrait de ces études les informations relatives aux caractéristiques et au contenu de tout type d'interventions, participants, résultats et méthodes, et un second auteur les a vérifiées. Pour cette mise à jour, nous avons réalisé des méta-analyses des interventions principales, en utilisant la méthode de variance inverse générique pour générer les rapports des cotes et les intervalles de confiance à 95 %.

Résultats principaux

Nous avons inclus 57 études (61 comparaisons) dans cette revue mise à jour. Nous avons trouvé 31 études concernant des interventions sur le lieu de travail destinées aux travailleurs individuels, comprenant la thérapie de groupe, l'accompagnement individuel, les matériels de développement personnel, la thérapie de substitution nicotinique et le soutien social, ainsi que 30 études examinant des interventions portant sur le lieu de travail dans son ensemble, c.-à.-d. les stimuli environnementaux, les mesures incitatives et les programmes globaux. Les essais étaient généralement de qualité modérée à élevée, et leurs résultats étaient cohérents avec ceux découverts dans d'autres contextes. Les programmes de thérapie de groupe (rapport des cotes (RC) pour le sevrage de 1,71, intervalle de confiance (IC) à 95 % de 1,05 à 2,80 ; huit essais, 1 309 participants), l'accompagnement individuel (RC 1,96, IC à 95 % 1,51 à 2,54 ; huit essais, 3 516 participants), les pharmacothérapies (RC 1,98, IC à 95 % 1,26 à 3,11 ; cinq essais, 1 092 participants) et les programmes d'interventions multiples visant principalement ou uniquement le sevrage tabagique (RC 1,55, IC à 95 % 1,13 à 2,13 ; six essais, 5 018 participants) ont tous augmenté les taux de sevrage en comparaison avec les groupes témoins sans aucun traitement ou bénéficiant d'une intervention minime. Les matériels de développement personnel étaient moins efficaces (RC 1,16, IC à 95 % 0,74 à 1,82 ; six essais, 1 906 participants), et deux programmes de prévention des rechutes (484 participants) n'ont pas aidé à maintenir l'abstinence à long terme. Les mesures incitatives n'ont pas semblé améliorer les chances de sevrage, à l'exception d'une étude qui a mis en évidence un bénéfice positif soutenu. Il y avait un manque de preuves quant à la réduction de la prévalence du tabagisme par les programmes globaux ciblant de multiples facteurs de risque.

Conclusions des auteurs

1. Nous avons trouvé des preuves solides indiquant que certaines interventions ciblant les fumeurs individuellement augmentaient la probabilité de sevrage. Celles-ci comprennent l'accompagnement individuel et en groupe, le traitement pharmacologique pour surmonter la dépendance à la nicotine, et les interventions multiples ciblant le sevrage tabagique en tant que résultat principal ou le seul. Toutes ces interventions montrent des effets semblables qu'elles soient proposées sur le lieu de travail ou ailleurs. Les interventions de développement personnel et le soutien social sont moins efficaces. Même si les personnes qui commencent ces interventions sont plus susceptibles d'arrêter, le nombre absolu de celles qui arrêtent effectivement est faible.

2. Nous n'avons détecté aucun effet des programmes globaux ciblant de multiples facteurs de risque sur la réduction de la prévalence du tabagisme, bien que ce résultat ne soit pas fondé sur une méta-analyse des données.

3. Il y avait des preuves limitées que la participation à des programmes pouvait être augmentée par des compétitions ou des incitations organisées par l'employeur, bien qu'un essai ait démontré un effet soutenu des récompenses financières pour suivre une cure de sevrage tabagique et pour le sevrage à long terme. Des recherches supplémentaires sont nécessaires pour établir quels composants de cet essai ont contribué à l'amélioration du taux de réussite.

4. D'autres recherches seraient utiles dans les pays à faible revenu et en voie de développement, où prévalent des taux de tabagisme élevés et où la législation anti-tabac n'est pas largement acceptée ou appliquée.

Plain language summary

Is the workplace an effective setting for helping people to stop smoking

Background
The workplace appears to be a useful setting for helping people to stop smoking. Large groups of smokers are available who can easily be reached and helped, using proven methods. It is also in the employers’ interests to improve the health of their workforce. Recent changes introducing anti-smoking laws in many developed countries may have eased the pressure to demonstrate the value of work-based programmes. The situation in developing countries still requires that such methods be tested and proved in those communities. We reviewed the evidence about workplace programmes to help employees stop smoking, and any information about their costs and benefits.

Study characteristics
For this updated review (first published in 2003), we searched for randomized and quasi-randomized controlled trials, comparing the success rates of those in a work-based stop-smoking programme with those not involved in a work-based stop-smoking programme. The comparison could be between people within a single worksite, or between one or more worksites randomized to a stop-smoking programme or to no programme (cluster-randomized). The study had to include adults (over 18), and could be in any language and reported in any format, published or not. It had to report the numbers stopping smoking for at least six months.

Results
We searched for studies in July 2013, and identified ten new trials that fitted our criteria, making a total for this update of 61 comparisons across 57 included studies. We grouped them into two broad categories: those aimed at helping individual smokers, and those that targeted the workplace environment as a whole. The first group includes such methods as individual or group counselling, self help, nicotine replacement therapy (NRT) and other medications, help from workmates or other staff, and helping quitters to stay smoke-free. The second group includes environmental cues (posters, reminders), financial or material incentives, and comprehensive smoking cessation or health promotion programmes. The review found that programmes based on group behaviour therapy (eight trials; 1309 participants), on individual counselling (eight trials; 3516 participants), on medications (five trials; 1092 participants), and on several interventions combined (six trials; 5018 participants) helped people to stop smoking. The chances of stopping smoking using these methods are about the same in the workplace as they are in other settings. This review found that the following do not help people to stop smoking when delivered in the workplace: self-help methods, support from friends, family and workmates, relapse prevention programmes, environmental cues, or comprehensive programmes aimed at changing several high-risk behaviours. Results were mixed for incentives, with one high-quality trial finding a clear benefit for incentives while the remaining five did not.

Quality of the evidence
Earlier studies tended to be less well-conducted and reported than recent ones. Fewer than one in five studies randomized their study population by an acceptable method. Two-thirds of the studies checked the accuracy of those who said they had quit by testing their breath, blood or urine. The results were generally in line with findings from other reviews of those ways of quitting in any setting. The 'Summary of findings' table shows that the trials were generally rated as being of moderate to high quality, further confirming the strength of our findings. Future research might examine what features of the large incentives trial made it more successful than other trials in that group. It would also be helpful to have more trials from developing and low-income countries, where smoking rates remain high and anti-smoking laws are not widely enforced.

概要

工作场所是否是帮助人们戒烟的有效途径

背景
工作场所似乎是帮助人们戒烟的有用环境。 大量的吸烟者可以使用成熟的方法轻松获得和得到帮助。 提高劳动者的健康水平也符合雇主的利益。 最近在许多发达国家引入反吸烟法的变化可能已经放宽了压力来显示基于工作的项目的价值。 发展中国家的情况仍然要求对这些方法进行测试和证明。 我们评价了工作场所项目中以帮助员工戒烟的证据,以及有关其成本和收益的任何信息。

研究特色
这次对综述(2003年首次发表)的更新,我们检索了随机和半随机对照试验,比较了基于工作的戒烟项目与不参与基于工作的戒烟项目的成功率。 比较可能在单个工作地内的人员之间,或者随机分配到戒烟项目或无戒烟项目(整群随机)的一个或多个工作地之间。 该研究纳入的必须是成年人(18岁以上),并且可以是任何语言,并以任何版本报告,发表或者未发表的。 必须报告停止吸烟至少6个月的数字。

结果
我们在2013年7月检索了研究,并确定了十项符合我们标准的新试验,这次更新共纳入57项包括61项比较。 我们将它们分为两大类:旨在帮助个体吸烟者以及针对整个工作环境的吸烟者。 第一组包括个人或团体咨询,自助,尼古丁替代疗法(NRT)和其他药物的方法,帮助同事或其他工作人员以及帮助戒烟者保持无烟的方法。 第二组包括环境线索(海报,提醒),财务或物质奖励,以及综合戒烟或健康促进项目。 本综述发现,基于团体行为治疗(8项试验,1309名参与者),个人咨询(8项试验,3516名参与者),药物治疗(5项试验,1092名参与者)和若干干预措施(6项试验,5018名参与者)帮助人们戒烟。 在工作场所或是其他场景中使用这些方法实现戒烟的可能性相同。 本综述发现,以下内容不能帮助人们在工作场所戒烟:自助方法,来自朋友、家庭和同事的支持,复发预防项目,环境线索或旨在改变多种高风险行为的综合计划。 有关激励,结果是混合的,一个高质量的试验发现明显的激励益处,而剩下的五个没有。

证据质量
早期的研究不如近期的研究实施和报告地好。 不到五分之一的研究通过可接受的方法将其研究人群随机化。 三分之二的研究通过检测呼吸,血液或尿液来验证自称戒烟的人的准确性。 本综述的结果与其他综述发现的在别的场景下实现戒烟的结果一致。 “结果总结”表显示,试验通常被评为中等到高等质量,进一步证实了我们的发现的实力。 进一步的研究可能会检查大型激励试验的哪些特征使其比该组中的其他试验更成功。 对吸烟率仍然很高,反吸烟法律也没有得到广泛执行的发展中国家和低收入国家进行更多的试验是有帮助的。

翻译注解

更新译者:严毓倩、王莹,审校:王莹。北京中医药大学循证医学中心。2017年5月30日

Résumé simplifié

Le lieu de travail est-il un cadre efficace pour aider les gens à arrêter de fumer ?

Contexte
Le lieu de travail semble offrir un cadre utile pour aider les gens à arrêter de fumer. Il est facile d'atteindre par ce biais des groupes importants de fumeurs afin de les aider en utilisant des méthodes éprouvées. Il est également dans l'intérêt des employeurs d'améliorer la santé de leur personnel. L'évolution récente et l'introduction des lois anti-tabac dans de nombreux pays développés peut avoir allégé la pression pour démontrer la valeur des programmes organisés sur le lieu de travail. En raison de la situation dans les pays en voie de développement, il est pourtant encore nécessaire de tester et éprouver de telles méthodes dans ces communautés. Nous avons examiné les preuves concernant les programmes sur le lieu de travail pour aider les employés à arrêter de fumer ainsi que toute information disponible sur les coûts et les bénéfices de ces programmes.

Caractéristiques des études
Pour cette revue mise à jour (publiée pour la première fois en 2003), nous avons recherché des essais contrôlés randomisés et quasi randomisés comparant les taux de réussite des personnes participant à un programme de sevrage tabagique sur le lieu de travail avec ceux des personnes n'étant pas impliqués dans un tel programme. La comparaison pouvait être effectuée entre des personnes sur un même lieu de travail, ou entre un ou plusieurs lieux de travail aléatoirement assignés à un programme de sevrage tabagique ou à l'absence de programme (randomisés en grappes). Les études devaient inclure des adultes (âgés de plus de 18 ans), et elles pouvaient être dans n'importe quelle langue et documentées dans n'importe quel format, publié ou non. Elles devaient rapporter le nombre de personnes arrêtant de fumer pendant au moins six mois.

Résultats
Nous avons recherché des études en juillet 2013, et avons identifié dix nouveaux essais remplissant nos critères d'inclusion, donnant pour cette mise à jour un total de 61 comparaisons dans les 57 études incluses. Nous les avons regroupées en deux grandes catégories : celles visant à aider les fumeurs individuellement, et celles ciblant le lieu de travail dans son ensemble. La première catégorie inclut des méthodes comme l'accompagnement individuel ou en groupe, le développement personnel, la thérapie de substitution nicotinique (TSN) et d'autres médicaments, le soutien des collègues de travail ou d'autres personnels, et l'assistance pour la prévention des rechutes aux personnes ayant arrêté de fumer. La deuxième catégorie inclut les stimuli environnementaux (posters, rappels), les incitations financières ou matérielles et les programmes globaux de sevrage tabagique ou de promotion de la santé. La revue a trouvé que les programmes basés sur la thérapie comportementale de groupe (huit essais ; 1 309 participants), sur l'accompagnement individuel (huit essais ; 3 516 participants), sur les médicaments (cinq essais ; 1 092 participants), et sur plusieurs interventions combinées (six essais ; 5 018 participants) aidaient les gens à arrêter de fumer. Les chances d'arrêter de fumer à l'aide de ces méthodes sont environ les mêmes sur le lieu de travail que dans d'autres contextes. Cette revue a découvert que les méthodes suivantes utilisées sur le lieu de travail n'aident pas les gens à arrêter de fumer : les méthodes de développement personnel, le soutien de la famille et des amis ou collègues, les programmes de prévention des rechutes, les stimuli environnementaux ou les programmes globaux destinés à modifier plusieurs comportements à haut risque. Les résultats étaient mitigés pour les mesures incitatives, un essai de bonne qualité constatant un bénéfice clair des mesures incitatives tandis que les cinq autres études n'en ont pas observé.

Qualité des preuves
Les études antérieures avaient tendance à être moins bien réalisées et documentées que les études plus récentes. Moins d'une étude sur cinq utilisait une méthode acceptable pour la randomisation des participants. Deux tiers des études vérifiaient la véracité des affirmations sur l'arrêt du tabagisme par des tests d'haleine, de sang ou d'urine. Les résultats étaient généralement en ligne avec ceux des autres revues sur ces méthodes de sevrage dans n'importe quel contexte. Le tableau 'Résumé des résultats' montre que les essais étaient généralement évalués comme étant de qualité modérée à élevée, ce qui conforte encore la force de nos résultats. Les recherches futures pourraient examiner quelles caractéristiques de l'essai à grande échelle portant sur les mesures incitatives ont permis un taux de réussite supérieur à celui des autres essais dans ce groupe. Il serait également utile d'avoir plus d'essais réalisés dans des pays en développement et à faible revenu, où les taux de tabagisme restent élevés et les lois anti-tabac ne sont pas largement appliquées.

Notes de traduction

Traduit par: French Cochrane Centre 22nd June, 2014
Traduction financée par: Financeurs pour le Canada : Instituts de Recherche en Santé du Canada, Ministère de la Santé et des Services Sociaux du Québec, Fonds de recherche du Québec-Santé et Institut National d'Excellence en Santé et en Services Sociaux; pour la France : Ministère en charge de la Santé

Laienverständliche Zusammenfassung

Ist der Arbeitsplatz ein effektiver Rahmen, um Menschen zu helfen, sich das Rauchen abzugewöhnen?

Hintergrund
Der Arbeitsplatz erweist sich als zweckmäßiger Rahmen, um Menschen zu helfen, sich das Rauchen abzugewöhnen. Es gibt große Gruppen von Rauchern, die leicht erreicht werden können und denen mithilfe bewährter Methoden geholfen werden kann. Auch steht es im Interesse des Arbeitgebers, die Gesundheit seiner Beschäftigten zu verbessern. Wahscheinlich hat der Druck, den Wert von arbeitsplatzbasierten Programmen beweisen zu müssen, aufgrund jüngster Veränderungen nachgelassen, die in vielen entwickelten Ländern die Einführung gesetzlicher Rauchverbote mit sich brachten. Aber die Situation in den Entwicklungsländern erfordert nach wie vor, dass derartige Methoden in diesen Gemeinschaften getestet werden und ihre Wirkung nachgewiesen wird. Wir überprüften die Evidenz für Programme am Arbeitsplatz, um Arbeitnehmern zu helfen, sich das Rauchen abzugewöhnen, sowie jegliche Auskunft in Bezug auf Kosten und Nutzen dieser Programme.

Studienmerkmale
Für diesen aktualisierten Review (erste Veröffentlichung 2003) suchten wir nach randomisierten und quasi randomisierten kontrollierten Studien, die die Erfolgsraten von Personen in arbeitsplatzbasierten Raucherentwöhnungsprogrammen mit den Erfolgsraten von Personen vergleichen, die nicht an arbeitsplatzbasierten Raucherentwöhnungsprogrammen teilnehmen. Der Vergleich fand statt zwischen Personen der gleichen Arbeitsstätte oder zwischen einer oder mehreren randomisierten Arbeitsstätten bei vorhandenem oder nicht vorhandenen Raucherentwöhnungsprogramm (cluster-randomisiert). Die Studien mussten Erwachsene (über 18) einschließen und durften in beliebiger Sprache und beliebigem Format verfasst und veröffentlicht oder unveröffentlicht sein. Sie mussten angeben, wie viele Personen mindestens sechs Monate lang mit dem Rauchen aufgehört haben.

Ergebnisse
Wir suchten nach Studien vom Juli 2013 und fanden zehn neue Studien, die unseren Kriterien entsprachen, was für diese Aktualisierung 61 Vergleiche über 57 eingeschlossene Studien ergab. Wir ordneten sie in zwei große Kategorien ein: solche, die darauf abzielten, einzelnen Rauchern zu helfen, und solche, die sich auf das Arbeitsumfeld als Ganzes richteten. Die erste Gruppe umfasste Methoden wie Einzel- oder Gruppenberatung, Selbsthilfe, Nikotinersatztherapien (NET) oder sonstige Medikamente, Hilfe von Arbeitskollegen oder anderen Personalmitgliedern und Hilfe für Raucher, die sich das Rauchen abgewöhnten, um rauchfrei zu bleiben. Die zweite Gruppe umfasste Wahrnehmungselemente in der Umgebung (Plakate, Gedankenstützen), finanzielle oder materielle Anreize und umfassende Raucherentwöhnungs- oder Gesundheitsförderungsprogramme. Der Review ergab, dass auf Gruppen-Verhaltenstherapie (acht Studien; 1309 Teilnehmer), auf persönlicher Beratung (acht Studien; 3516 Teilnehmer), auf Medikamenten (fünf Studien; 1092 Teilnehmer) und auf Kombinationen mehrerer Interventionen (sechs Studien; 5018 Teilnehmer) basierende Interventionen Rauchern halfen, mit dem Rauchen aufzuhören. Die Chancen, bei Anwendung dieser Methoden mit dem Rauchen aufzuhören, sind am Arbeitsplatz in etwa genauso groß wie in anderen Umgebungen. Dieser Review ergab, dass folgende Methoden Rauchern nicht helfen, wenn sie am Arbeitsplatz bereitgestellt werden: Selbsthilfe-Methoden, Unterstützung durch Freunde, Familie und Arbeitskollegen, Rückfallprophylaxeprogramme, Wahrnehmungselemente in der Umgebung sowie umfassende Programme, die auf die Veränderung risikoreicher Verhaltensweisen abzielen. Bei den Anreizen waren die Ergebnisse gemischt. Eine qualitativ hochwertige Studie ermittelte einen deutlichen Nutzen von Anreizen, die fünf weiteren Studien nicht.

Qualität der Evidenz
Ältere Studien neigten zu einer weniger guten Durchführung und Berichterstattung als jüngere Studien. In weniger als einer von fünf Studien wurde die Studienpopulation mit einer akzeptablen Methode randomisiert. In zwei Dritteln der Studien wurden die Aussagen derjenigen, die angaben, dass sie mit dem Rauchen aufgehört hatten, anhand von Atem-, Blut- oder Urinproben auf ihre Richtigkeit geprüft. Diese Ergebnisse stimmen allgemein mit Ergebnissen aus anderen Reviews über diese Entwöhnungsmethoden in einem beliebigen Kontext überein. Die Ergebnisübersichtstabelle zeigt, dass die Qualität der Studien im Allgemeinen als moderat bis hoch bewertet wurde, was die Belastbarkeit unserer Ergebnisse zusätzlich bestätigt. In zukünftigen Forschungsarbeiten könnte untersucht werden, welche Merkmale der großen Studie über Anreize sie erfolgreicher machten als andere Studien dieser Gruppe. Auch wären mehr Studien aus Entwicklungsländern und einkommensschwachen Ländern hilfreich, in denen die Raucherquoten nach wie vor hoch sind und gesetzliche Rauchverbote nicht flächendeckend durchgesetzt werden.

Anmerkungen zur Übersetzung

Koordination durch Cochrane Schweiz

Streszczenie prostym językiem

Czy w zakładzie pracy można skutecznie wspomagać rzucanie palenia?

Wprowadzenie
Można sądzić, że zakład pracy to dobre miejsce udzielania pomocy w rzucaniu palenia. W takich miejscach łatwo dotrzeć do dużych grup osób palących oraz pomagać im wykorzystując sprawdzone metody. Poprawa zdrowia pracowników jest również w interesie pracodawców. Wprowadzenie przepisów antytytoniowych w wielu krajach rozwiniętych mogło zmniejszyć nacisk na potrzebę wykazywania wartości programów realizowanych w zakładach pracy. W krajach rozwijających się sytuacja wciąż wymaga oceny skuteczności metod stosowanych w takich warunkach. Dokonaliśmy przeglądu danych na temat programów w zakładach pracy, które mają pomóc zatrudnionym rzucić palenie, uwzględniając ich koszty i korzyści.

Charakterystyka badań
W obecnej aktualizacji przeglądu (opublikowanego po raz pierwszy w 2003 r.) uwzględniliśmy badania z randomizacją i z pseudo-randomizacją. Odsetki osób rzucających palenie dzięki uczestnictwu w programach realizowanych w miejscu pracy porównywano z odsetkami osób rzucających palenie niebiorących udziału w takich programach. Porównania dokonywano między osobami w tym samym zakładzie pracy albo pomiędzy różnymi zakładami, losowo wyznaczanymi do brania lub niebrania udziału w programie (randomizacja grupowa). Badania dotyczyły osób dorosłych (powyżej 18 lat); mogły być opublikowane lub nie, w dowolnym języku i formacie. Wymagane było podanie liczby osób, które zaprzestały palenia na co najmniej 6 miesięcy.

Wyniki
Wyszukiwanie badań przeprowadzono w lipcu 2013 r. i znaleziono 10 nowych badań spełniających kryteria. Łącznie zaktualizowany przegląd obejmuje 61 porównań z 57 zakwalifikowanych badań. Badania podzielono na dwie kategorie: dotyczące indywidualnej pomocy palaczom oraz obejmujące interwencje w miejscu pracy skierowane do całej populacji palących. Pierwsza grupa obejmuje takie metody, jak poradnictwo indywidualne lub grupowe, samopomoc, nikotynowa terapia zastępcza (NTZ) oraz inne leki, wsparcie przez kolegów i innych współpracowników oraz pomoc osobom rzucającym palenie w utrzymaniu abstynencji. Druga grupa badań obejmowała środowiskowe działania (plakaty, przypomnienia), zachęty finansowe i rzeczowe oraz kompleksowe programy antynikotynowe lub programy promocji zdrowia. Przegląd wykazał, że pomocne w rzucaniu palenia są programy oparte na grupowej terapii behawioralnej (8 badań; 1309 uczestników), indywidualnym poradnictwie (8 badań; 3516 uczestników), stosowaniu terapii farmakologicznej (5 badań; 1092 uczestników) oraz programy łączące różne działania (6 badań; 5018 uczestników). Stosowanie tych metod w miejscu pracy wiąże się z podobną szansą na zaprzestanie palenia jak stosowanie w innych miejscach. W przeglądzie wykazano, że metody takie jak samopomoc, wsparcie znajomych, rodziny, współpracowników, cykliczne programy profilaktyczne, działania środowiskowe lub kompleksowe programy ukierunkowane na zmianę ryzykownych zachowań nie są skuteczne we wspomaganiu rzucania palenia w miejscu pracy. Wyniki nie były jednoznaczne w odniesieniu do stosowania zachęt. Tylko w jednym z sześciu badań wysokiej jakości wykazano wyraźne korzyści.

Jakość danych naukowych
Jakość przeprowadzenia i sposób prezentacji starszych badań były gorsze w porównaniu do nowszych badań. W mniej niż jednym na pięć badań dokonano randomizacji odpowiednimi metodami. W dwóch trzecich badań weryfikowano deklaracje uczestników o zaprzestaniu palenia za pomocą badań wydychanego powietrza, krwi lub moczu. Otrzymane wyniki są zasadniczo zgodne z wynikami innych przeglądów, które oceniały sposoby rzucania palenia w różnych środowiskach. Tabela "Podsumowanie wyników" pokazuje, iż generalnie badania były umiarkowanej i wysokiej jakości, co potwierdza siłę przedstawionych wniosków. W przyszłości warto zbadać, dlaczego w jednym dużym badaniu stosowanie zachęt było skuteczniejsze niż w innych badaniach z tej kategorii. Przydałoby się też więcej badań w krajach rozwijających się oraz o niskich dochodach, gdzie odsetek palących jest nadal wysoki, a przepisy antytytoniowe nie są powszechnie egzekwowane.

Uwagi do tłumaczenia

Tłumaczenie: Magdalena Koperny, Redakcja: Łukasz Strzeszyński

Ringkasan bahasa mudah

Adakah tempat kerja persekitaran yang berkesan bagi membantu orang ramai berhenti merokok

Latar belakang
Tempat kerja dilihat sebagai persekitaran yang sesuai bagi membantu orang ramai berhenti merokok. Terdapat kumpulan besar perokok, yang boleh dihubungi dan dibantu, menggunakan kaedah yang telah dibuktikan. Adalah juga menjadi kepentingan majikan untuk menambahbaik kesihatan tenaga pekerja mereka. Perubahan terbaru yang memperkenalkan undang-undang anti-merokok dalam banyak negara-negara maju mungkin telah meringankan tekanan untuk menunjukkan nilai program yang berasaskan kerja. Situasi dalam negara-negara membangun masih memerlukan kaedah-kaedah tersebut diuji dan dibuktikan dalam kalangan komuniti mereka. Kami mengulas bukti mengenai program-program tempat kerja untuk membantu pekerja-pekerja berhenti merokok, dan maklumat mengenai kos dan manfaatnya.

Ciri-ciri kajian.
Untuk ulasan yang dikemaskini ini (penerbitan pertama dalam tahun 2003), kami mencari ujikaji-ujikaji terkawal secara rawak dan separa-rawak ('quasi-randomized'), membandingkan kadar kejayaan mereka yang berada dalam program berhenti merokok berasaskan kerja dengan mereka yang tidak terlibat dalam program berhenti merokok berasaskan kerja. Perbandingan mungkin antara orang ramai dalam satu tempat kerja, atau diantara satu atau lebih tempat kerja yang diatur dibahagi rawak kepada program berhenti merokok atau kepada tanpa program (perawakan kluster/kelompok). Kajian perlu melibatkan orang dewasa (lebih 18 tahun), dan boleh dilakukan dalam mana-mana bahasa dan dilaporkan dalam mana-mana format, samada diterbitkan ataupun tidak. Ia perlu melaporkan bilangan berhenti merokok untuk sekurang-kurangnya enam bulan.

Keputusan
Kami mengkaji ujikaji-ujikaji dalam Julai 2013 dan mengenalpasti sepuluh ujikaji baru yang menepati kriteria kami, menjadikan jumlah untuk bahan yang dikemaskini ini sebanyak 61 perbandingan merentas 57 ujikaji yang terlibat. Kami membahagikan mereka ke dalam dua kategori besar: satu bertujuan membantu perokok individu, dan satu tertumpu kepada persekitaran tempat kerja secara keseluruhan. Kumpulan pertama merangkumi kaedah-kaedah termasuk memberi khidmat kaunsel secara individu ataupun kumpulan, bantuan terkendiri, terapi gantian nikotin (NRT) dan ubatan lain, bantuan daripada rakan sekerja ataupun pekerja lain, dan membantu perokok yang telahpun berhenti merokok supaya dapat dikekalkan bebas rokok. Kumpulan kedua merangkumi aspek-aspek persekitaran (poster, peringatan), insentif kewangan ataupun bahan, dan program-program komprehensif berhenti merokok ataupun promosi kesihatan. Ulasan mendapati program-program yang berasaskan kumpulan terapi tingkah-laku (lapan ujikaji; 1309 peserta), berasaskan kaunseling individu (lapan ujikaji; 3516 peserta), berasaskan ubatan (lima ujikaji; 1092 peserta), dan berasaskan kombinasi beberapa intervensi (enam ujikaji; 5018 peserta) telah dapat membantu orang ramai berhenti merokok. Peluang berhenti merokok menggunakan kaedah-kaedah ini adalah lebih kurang sama di tempat kerja dan juga di lain-lain persekitaran. Ulasan ini mendapati yang berikut tidak dapat membantu orang ramai untuk berhenti merokok apabila ia dilakukan di tempat kerja: kaedah bantuan kendiri, sokongan rakan-rakan, keluarga dan rakan sekerja, program pencegahan ulangan, aspek-aspek persekitaran, atau program komprehensif yang tertumpu kepada penukaran beberapa tingkah-laku yang berisiko tinggi. Keputusan adalah bercampur bagi insentif, di mana satu ujikaji berkualiti tinggi mendapati manfaat yang jelas bagi insentif manakala lima selebihnya tidak.

Kualiti bukti.
Kajian-kajian awal tidak dijalankan dan dilaporkan dengan begitu baik berbanding dengan yang baru. Kurang daripada satu dalam lima kajian yang telah merawakkan populasi kajian mereka dengan menggunakan kaedah yang boleh diterima. Dua pertiga daripada kajian telah memeriksa ketepatan mereka yang mengatakan telah berhenti merokok dengan melakukan pemeriksaan ke atas nafas, darah ataupun air kencing. Keputusan secara umumnya selaras dengan penemuan dari ulasan-ulasan lain mengenai cara berhenti merokok dalam mana-mana persekitaran. Gambarajah Ringkasan Penemuan menunjukkan pada umumnya, kualiti kajian-kajian dinilai sebagai sederhana hingga tinggi, dan ini mengesahkan kekuatan penemuan kami. Penyelidikan di masa hadapan mungkin boleh mengkaji apakah ciri-ciri ujikaji insentif besar yang telah menjadikannya lebih berjaya berbanding dengan ujikaji-ujikaji lain dalam kumpulan tersebut. Ia juga akan membantu untuk mempunyai lebih banyak ujikaji daripada negara-negara membangun dan berpendapatan rendah, di mana kadar merokok kekal tinggi dan undang-undang anti-merokok tidak dikuatkuasakan dengan luasnya.

Catatan terjemahan

Diterjemahkan oleh Noor Salwah S Omar (Universiti Sains Malaysia). Disunting oleh Tuan Hairulnizam Tuan Kamauzaman (Universiti Sains Malaysia). Untuk sebarang pertanyaan berkaitan terjemahan ini sila hubungi salwah@usm.my.

Summary of findings(Explanation)

Summary of findings for the main comparison. Smoking cessation interventions for the workplace
  1. 11 +outlier (Glasgow 1994); removing this study reduced the OR to 1.62 (0.98 to 2.66).
    2Removing self-reported (non-validated) abstinence studies made no significant difference to the results.
    3No funnel plot - too few studies.
    4Removing trials at high risk of bias made no difference
    5Possibility of publication bias
    6One trial (Volpp 2009) has 37% of the weight and is the only trial with positive findings. Removing it eliminates the statistical significance (OR 1.16 [0.73 to 1.83]).
    7Two non-validated, two partial validation, one 'bogus pipeline' and one CO.

Smoking cessation interventions for the workplace
Patient or population: Employees who smoke
Settings: Workplaces
Intervention: Smoking cessation interventions
OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
Control Smoking cessation interventions
Group therapy
Follow-up: 6-24 months
51 per 1000 84 per 1000
(54 to 131)
OR 1.71
(1.05 to 2.80)
1309
(8 studies)
⊕⊕⊕⊝
moderate 1,2,3
 
Individual counselling
Follow-up: 6-24 months
61 per 1000 113 per 1000
(89 to 141)
OR 1.96
(1.51 to 2.54)
3516
(8 studies)
⊕⊕⊕⊝
moderate 3,4,5
 
Self-help interventions
Follow-up: 6-24 months
45 per 1000 52 per 1000
(34 to 79)
OR 1.16
(0.74 to 1.82)
1906
(6 studies)
⊕⊕⊕⊕
high 2,3
 
Pharmacological interventions
Follow-up: 6-24 months
77 per 1000 142 per 1000
(95 to 206)
OR 1.98
(1.26 to 3.11)
1092
(5 studies)
⊕⊕⊕⊕
high 3,4
Limiting to NRT only (4 studies) reduced OR to 1.81 (1.07 to 3.08).
Incentives
Follow-up: 6-18 months
73 per 1000 113 per 1000
(82 to 154)
OR 1.60
(1.12 to 2.3)
1928
(5 studies)
⊕⊕⊕⊝
moderate 3,6
 
Multiple interventions
Follow-up: 6-36 months
63 per 1000 95 per 1000
(71 to 126)
OR 1.55
(1.13 to 2.13)
5018
(6 studies)
⊕⊕⊕⊝
moderate 3,4,7
 
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; OR: Odds ratio;
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Background

Most adults spend about a third of their day in a workplace environment. The workplace is therefore a setting through which large groups of smokers can potentially be reached by health promotion (Gruman 1993).

Description of the condition

It is estimated that in 2007 approximately 60% of Americans were covered by health insurance plans sponsored through their or their spouse's workplace (DeNaves-Walt 2008). Milani 2009 estimates that in the US nearly 60% of after-tax profits are spent on corporate health benefits, with 80% of such expenses incurred by 10% to 20% of the workforce. US employers have a vested interest in improving and maintaining the health and performance of their workforce.

National smoke-free policies introduced in the UK in 2006-7 are complemented by government guidelines on how to implement the policies and how best to assist employees with smoking cessation during this process (NICE 2007). Recommendations include summaries of interventions of proven efficacy, and encouragement for employers conducting smoking cessation programmes within working hours. The cost-effectiveness of such implementation has also been tested (NICE 2006).

Description of the intervention

Work-based smoking cessation programmes are similar to those deployed in other institutions (e.g. hospitals, colleges, schools) or in the community. They include behavioural or pharmacological interventions, or a combination of both, and comprehensive health promotion initiatives, targeting individuals or cohorts of workers. Proven cessation strategies can be conducted opportunistically on workplace premises and in working hours.

How the intervention might work

There are several advantages to the traditional workplace as a setting for smoking cessation:

  1. It provides access to a large number of people who make up a relatively stable population.

  2. It has the potential for higher participation rates than non-workplace environments.

  3. It may encourage sustained peer-group support and positive peer pressure.

  4. It provides a particular opportunity to target young men, who traditionally have low general practitioner consultation rates and are thus less likely to benefit from opportunistic health promotion activity in primary care.

  5. Occupational health staff may be on hand to give professional support.

  6. The employee generally is not required to travel to the programme or to dedicate their own personal time to it.

However, all of these assumptions are based on a model of the workplace that is rapidly changing. Recent research, included in this update, highlights the increasingly transient and volatile nature of the modern workforce, with younger employees changing jobs and locations more frequently than earlier generations (see for example Mishra 2010; Okechukwu 2009).

Why it is important to do this review

During the life of this review (first published ten years ago), smoke-free legislation has fundamentally altered working conditions in many developed countries. The attention of the tobacco control community is now shifting to areas where anti-tobacco initiatives are still in their infancy. We include new studies in this update which test such approaches in India, Malaysia and China, with varying levels of success.

Objectives

The specific objectives of this updated review were:

1. To categorize workplace interventions for smoking cessation tested in controlled studies, and to determine the extent to which they help workers to stop smoking.

2. To collect and evaluate data on costs and cost effectiveness associated with workplace interventions.

Methods

Criteria for considering studies for this review

Types of studies

We include randomized and quasi-randomized controlled trials, allocating individuals, workplaces or companies to intervention or control conditions.

Types of participants

Adults over 18 years of age, in employment, who smoked.

Types of interventions

In earlier versions of this review, we divided the interventions into those aimed at helping individual smokers to quit, and those aimed at the workplace as a whole. Although we still include both types of interventions, previous versions of this review also included bans and restrictions as interventions aimed at the workplace as a whole. These are now covered by a companion review (Callinan 2010), and we no longer include them here.

We include any workplace interventions aimed at smoking cessation. These include programmes designed to exclusively target smoking behaviour or to target multiple lifestyle risk behaviours. The studies aim mainly to assess the effects of cessation programmes for individual workers who smoke. They test a range of interventions, including individual and group counselling, self-help materials, pharmacological therapy, social and environmental support, incentives, and comprehensive programmes. They are usually aimed at individuals who seek help rather than at the workforce as a whole. We also include studies that test relapse prevention interventions in association with worksite-based smoking cessation programmes.

Types of outcome measures

The main outcome was employee smoking behaviour (cessation rates for programmes and workplace prevalence data), for a minimum of six months. We preferred prolonged or continuous abstinence to point prevalence, and biochemically verified abstinence to self-report, but did not exclude studies on the basis of their chosen outcomes. We excluded studies with less than six months follow-up.

Search methods for identification of studies

We searched the Cochrane Tobacco Addiction Review Group Specialized Register, which includes studies identified by systematic electronic searches of multiple databases, handsearching of specialist journals and conference proceedings, and grey literature (i.e. conference proceedings and unpublished reports not normally covered by most electronic indexing systems). At the time of the search, the Register included the results of searches of the Cochrane Central Register of Controlled Trials (CENTRAL), issue 12, 2012; MEDLINE (via OVID) to update 20130607; EMBASE (via OVID) to week 201324; and PsycINFO (via OVID) to update 20130610. See the Tobacco Addiction Group module in The Cochrane Library for full search strategies and a list of other resources searched. See Appendix 1 for the search terms used to search the Register for this review. These searches include terms to identify controlled trials. We also conducted ad hoc searches of MEDLINE, EMBASE and PsycINFO using topic-related keywords without design limits. These searches were updated on 2nd July 2013. Search terms included 'worksite*' or 'workplace*' as keyword or free-text terms, and 'work' or 'occupational health' as keywords. We list the search strategies in Appendix 2. The results of these searches were cross-checked against references in the identified papers and previous reviews and meta-analyses.

We also contacted authors of studies for additional information where necessary.

Data collection and analysis

Selection of studies

One author (KC) prescreened reports for relevance, i.e. studies that might be included, or for useful background, and obtained full-text copies of candidate studies for inclusion. Both authors then independently assessed them against the inclusion criteria, resolving discrepancies by discussion. We noted reasons for the non-inclusion of studies, and incorporated those into the Characteristics of excluded studies table.

Data extraction and management

One author (KC) extracted data and a second author (TL) checked them. Where possible, we extracted data on quit rates using the number randomized as the denominator, making the assumption that those lost to follow-up (or not reported) continued to smoke.

Assessment of risk of bias in included studies

For this update, we have evaluated all the included studies (past and new) for risks of bias, using the Cochrane 'Risk of bias' assessment tool (Cochrane Handbook, Chapter 8). We have assessed the randomization process (sequence generation and allocation concealment; selection bias), blinding (performance and detection bias), incomplete outcome reporting (attrition bias), and selective outcome reporting (reporting bias).

Dealing with missing data

We contacted authors where possible to fill gaps in the data. We counted participants lost to follow-up or unaccounted for as continuing smokers, and where possible included them in the denominator on an intention-to-treat basis.

Data synthesis

For this update, we have pooled data for the main categories of intervention, using the generic inverse variance (GIV) method (derived from the log odds), to produce Mantel-Haenszel odds ratios (ORs), using a fixed-effect model with 95% confidence intervals (CIs). We have used the intraclass correlation coefficient reported by Martinson 1999 (ICC for percentage quit smoking in worksite) to obtain an adjusted estimate of the effect size for the studies that were cluster-randomized. This represents a departure from the Cochrane Tobacco Addiction Group's preferred analysis method of risk ratios, in order to accommodate the ICC calculations where necessary.

We include a 'Summary of findings for the main comparison' for the main results.

We also include a glossary of tobacco-related terms (Appendix 3).

Results

Description of studies

We found 57 studies meeting the inclusion criteria. Ten of these are new for this update (Bergstrom 2008; Prochaska 2008; Milani 2009; Okechukwu 2009; Volpp 2009; Hishida 2010; Mayer 2010; Mishra 2010; Groeneveld 2011; Noor 2011). Detailed information about each is shown in the table Characteristics of included studies. We assigned the individual studies to one or more of the categories of intervention. Four studies (Omenn 1988; Windsor 1988; Gomel 1993a; Tanaka 2006) contribute to more than one category. For this update, we identified eight additional studies that did not meet the inclusion criteria, and we also now exclude four trials that were originally included (Kornitzer 1987; Jeffery 1988; Burling 1989; Burling 2000). This gives a total for this update of 105 excluded studies, brief details of which are listed in the table Characteristics of excluded studies. We also identified two ongoing studies (NCT01124110 2012; NTR8148 2012), and one Chinese study (Gao 2010) for which we currently have insufficient information to include it.

A number of studies evaluated interventions aimed at the individual, usually without any attempt to target or modify the workplace as a whole. The types of intervention were diverse, including intensive behavioural interventions, self-help materials, pharmacological treatments, and social support.

Other studies included environmental support for not smoking, incentives for not smoking, and multicomponent programmes aimed primarily at smoking cessation, or at improving employees' general health, including their smoking status.

GROUP 1: INTERVENTIONS AIMED AT THE INDIVIDUAL TO PROMOTE SMOKING CESSATION

1. Intensive behavioural interventions: Group counselling

We found 10 randomized controlled trials that reported 6- to 24-month quit rates for individuals receiving group-based behavioural interventions (Glasgow 1984; Frank 1986; Klesges 1987; Omenn 1988; DePaul 1994; Razavi 1999; Schröter 2006; Gunes 2007; Mayer 2010; Mishra 2010). Some of these studies compared an intensive intervention, typically including group support meetings, with a less intensive intervention such as provision of self-help materials, or with a waiting list control. Some compared variations of group programmes, or the additional impact of incentives.

Three studies evaluated ways to improve the results of group programmes:

  • Glasgow 1984 compared three versions of a controlled smoking programme in 36 employees: abrupt reduction; gradual reduction; or gradual reduction plus feedback on nicotine consumption with one pre- and two post-tests. Smoking reduction was defined as an outcome for this study, targeting nicotine content (brand smoked), number of cigarettes smoked daily, and percentage of each cigarette smoked. Participants could choose either cessation or reduction as their desired outcome. The participation rate was not reported, though an 8% attrition rate was reported.

  • Frank 1986 assigned 63 participants to one of three treatments: four hypnotic sessions with a booster; two hypnotic sessions; or two hypnotic and two behavioural sessions with a booster. A follow-up group of 15 later recruits received four hypnotic sessions and a booster session. The participation rate was not reported. The study lacked a no-treatment control group.

  • Klesges 1987 tested the effect of competitions on cessation rates in 136 smokers from eight workplaces. The workplace was the unit of randomization (cluster-randomized) but with individuals as the unit of analysis. The participation rate was not reported but was estimated at 28% across all eight participating workplaces. The drop-out rate from treatment was 7% overall, with no difference across conditions.

DePaul 1994) compared three interventions; self-help alone, self-help with incentive payments for days abstinent, and intensive group support with incentive payments, cognitive behavioural strategies, and maintenance manuals.

Two group-counselling trials (Razavi 1999; Mayer 2010) targeted recent ex-smokers, to reinforce abstinence and reduce relapse rates. Three other trials (Klesges 1987; Omenn 1988: Schröter 2006) also included a relapse prevention component, alongside a cessation intervention.

  • Razavi 1999 randomized abstainers (98.6% of those eligible) who had completed a non-randomized cessation programme, to test the efficacy of two relapse prevention programmes. Participants were assigned to a psychologist-run support group (PG), or an ex-smoker-run support group (SG) or a 'no formal support' group (NG), and were assessed at 12 months. Participants in the PG and SG groups attended monthly meetings, where cessation support was given, and weight, blood pressure, pulse and concomitant medical problems were monitored. At the end of nine months, participants completed a Brief Symptoms Inventory and a Life Events Scale. All who were participants at three months were followed up until 12 months post-treatment.

  • Mayer 2010 randomized successful quitters following a smoking cessation programme in a number of Belgian companies to either work-based group counselling or to proactive phone counselling to minimize relapse rates. The cohorts were assessed after nine months for long-term relapse-free quit rates.

Omenn 1988 recruited smokers at a single workplace. Participants with a preference for a group format were randomized to one of two smoking cessation programmes (Multiple Component Programme or Relapse Prevention Programme) or to a 'self help only' condition (American Cancer Society Quitter's Guide). Those not interested in group support were randomized to a manual-based version of the same Multiple Component Programme or Relapse Prevention Programme, or the same Guide. The participation rate was 11%. This study also contributes data to the self-help group.

Schröter 2006 offered a relapse prevention programme in four German workplaces, compared with a standard behavioural programme. Nicotine replacement therapy was also provided if requested. Sessions rather than individuals were randomized, and the programme lasted eight weeks, with follow-up at one year.

Gunes 2007, set in a Turkish textile factory, primarily measured movement through stages of change in two matched cohorts of male smokers. The intervention group received a three-week behavioural programme based on the American Lung Association's Seven Steps to a Smoke-Free Life. Smoking status was assessed at the six-month follow-up.

Mishra 2010 is a study set in four Indian call centres, each of which hosted a different level of intervention. The control site distributed self-help materials to all employees on the hazards of tobacco, methods of quitting, and where to go for practical help. The first intervention site (which we use in this review) conducted health education sessions for all employees, followed by focus-group discussions for tobacco users in groups of 7 to 10. The second intervention site replicated this but added one-to-one behavioural therapy, and the third intervention site added the offer of bupropion based on needs assessment. The researchers followed up all tobacco users in person or by phone to 12 months. It is notable that high staff turnover in this population meant that 52.4% of baseline tobacco users had changed jobs after 12 months.

2. Intensive behavioural interventions: Individual counselling

We found eight studies that investigated individual counselling, in most cases given by a physician (Cambien 1981; Li 1984; Gomel 1993a; Kadowaki 2000; Lang 2000), in Terazawa 2001 by trained nursing staff, in Groeneveld 2011 by either an occupational physician or an occupational nurse, and in Windsor 1988 by a 'health educator'.

Two years post-intervention, Cambien 1981 followed up the first 1292 participants in a cluster-randomized controlled trial, the Paris Cardiovascular Risk Factor Prevention Trial, conducted in 160 sections of a civil service administration. They measured the effects of physician advice, information leaflets and physical monitoring on diet, alcohol and cigarette consumption in young men (25 to 35 years of age). We focus here on the 610 participants in the smoking cessation components. The intervention participants received either three or four tailored counselling sessions, depending on whether their baseline assessment showed them to be at low or at high risk of coronary disease. The control group received only baseline and follow-up assessments.

Li 1984 studied asbestos-exposed male smokers undergoing screening in a mandated programme for naval shipyard workers. The workers were categorized as having normal or abnormal pulmonary status on the basis of a chest X-ray and pulmonary function tests. They were then randomly assigned within pulmonary function test categories to receive either a simple warning or three to five minutes of behavioural cessation counselling from the physician who gave them the results of their pulmonary tests. The participation rate is reported as 84.6%. The study did not have a no-treatment control group.

Windsor 1988 studied the incremental effectiveness of a skills training programme with social support enhancement and monetary incentives to a self-help manual. A health educator provided training in cessation skills in a structured 20- to 30-minute one-to-one session; one group received this training to supplement the self-help manual, and another group received both interventions plus monetary incentives. This study also contributes data to the incentives group.

Gomel 1993a randomized 28 Sydney (Australia) ambulance stations to four intervention groups (without a no-treatment control), in an attempt to reduce cardiovascular risk factors. The HRA (Health Risk Assessment) group received measurements and risk assessments, including body mass index, blood pressure, cholesterol, smoking status, percentage of body fat, and aerobic capacity. We focus here on the 128 smokers who participated. Those assessed as being at high risk were referred to their own family physician, but received no direct support from the intervention programme. The RFE (Risk Factor Education) group received a similar assessment, but were given standard advice, through written and video material. The BC (Behavioural Counselling) group, after the standard assessment, were offered up to six counselling sessions in risk reduction, together with a manual on behaviour change. The fourth group (BCI, Behavioural Counselling and Incentives) received the same programme as the BC group, together with an incentive scheme which gave individuals the chance to win AUD 40 for achieving risk reduction targets at three and six months, plus a prize of AUD 1000 for the station which achieved the highest percentage of successful participants at six-month follow-up. The participation rate was 88% (431 participants, including 128 smokers). This study also contributes data to the incentives group.

Kadowaki 2000 evaluated the effectiveness of a smoking cessation intervention in all male smokers in a Japanese radiator manufacturing factory. Participants in the intervention group received individual counselling by a doctor, and those who signed a Smoking Cessation Declaration underwent a five-month intervention. Subjects in the control group received equivalent delayed intervention after four months. Randomization was by individual smoker.

Lang 2000 compared the effects of a workplace intervention by the occupational physician, offering simple advice on smoking cessation for five to ten minutes, with a more active strategy of advice including a quit date and extra support. For both strategies, the medical team was composed of a physician and whenever possible a nurse, who would reinforce the physician's advice. Both the randomization and the analysis were by workplace.

Terazawa 2001 randomized 228 smokers presenting for routine occupational health checks in a Japanese factory; 117 were allocated to the intervention condition, and 111 to the control. All participants completed a baseline questionnaire and had carbon monoxide (CO) and urinary metabolites measured to verify their level of smoking. Intervention group smokers also received a 15- to 20-minute counselling session from a nurse trained in cessation methods, and those who were prepared to set a quit date received four follow-up phone calls to support their quit attempt. Control subjects received the baseline screening and usual care. All participants were re-assessed at six and twelve months follow-up.

Groeneveld 2011 targeted individuals at elevated risk for cardiac illness in a cohort of Dutch male construction workers. The participants could choose to address either nutrition and physical activity or smoking cessation, and we focus for this review on the 115 intervention smokers and the 123 control smokers who attempted to quit smoking. The programme offered three face-to-face 45- to 60-minute sessions of motivational interviewing (MI) counselling, and four 15- to 30-minute phone calls with an occupational physician or nurse. All participants also received brochures on physical activity, healthy eating, smoking, and cardiovascular disease. The relevant outcome was self-reported smoking cessation at six and 12 months.

3. Self-help interventions

We found six studies that examined self-help interventions (Omenn 1988; Sutton 1988a; Sutton 1988b; Sutton 1988c; Sutton 1988d; Hishida 2010). A variety of approaches were tested and included short videos (Sutton 1988a; Sutton 1988b; Sutton 1988c; Sutton 1988d), self-help manuals (Omenn 1988), and information about genotyping (Hishida 2010).

The Omenn 1988 study is described in the Group Counselling section. We consider only the self-help arms for this category.

Sutton (Sutton 1988a; Sutton 1988b; Sutton 1988c; Sutton 1988d), in a series of four randomized controlled studies in four UK companies, evaluated a minimal smoking intervention programme based on the use of motivational videotapes. In the videotape studies groups of smokers (n = 603) were randomly assigned to watch one of several different videotapes. They were followed up along with non-participants (n = 1015) at three months and again at one year.

Hishida 2010 was set in a Tokyo bank, and allocated smokers to genotyping or to assessment only by alternate months of routine occupational health checks. All smokers received a booklet indicating that particular genotypes appeared to be at increased risk of smoking-related cancers; those in the intervention cohort who agreed to be genotyped received their results three months later, without specific cessation advice. All participants were assessed at 12 months. The primary outcome was movement through the stages of change, but smoking status by allocated group and by genotype were also collected.

4. Pharmacological therapy

Five studies investigated pharmacological therapy in the workplace (Sutton 1987; Sutton 1988e; Kornitzer 1995; Rodriguez 2003; Noor 2011). Seven other included studies (Razavi 1999; Schröter 2006; Tanaka 2006; Sorensen 2007; Okechukwu 2009; Bergstrom 2008; Mayer 2010) also included NRT as part of their intervention, but not as the component being tested. Mishra 2010 added bupropion to its most intensive intervention arm, but only 10 of the 24 smokers who were offered bupropion took up the option.

Kornitzer 1995 evaluated the effects of adding nicotine gum to smokers already using the nicotine patch in a double-blind placebo-controlled randomized trial. The effect of the nicotine patch against placebo patch in both groups receiving placebo nicotine gum was also assessed.

Sutton 1987 evaluated the effectiveness of a brief treatment for smoking using nicotine chewing gum in a large retailing company in London, UK. The study was randomized with a two-group pre-test/post-test design. In total 270 of 334 cigarette smokers who expressed interest were invited to take part in the programme, which consisted of two individual consultations two weeks apart and a prescription for 2 mg Nicorette gum with recommendations for its use. The remaining 64 smokers constituted a no-intervention control group.

Sutton 1988e evaluated the effect of offering brief individual treatment based on nicotine chewing gum to a randomly chosen sample in one company (n = 161) still smoking at the three-month follow up to a previous video intervention (Sutton 1988d). The treatment course was administered by occupational health nurses and consisted of four short consultations over a 12-week period.

Rodriguez 2003 delivered a combined intervention of individual structured counselling with nicotine patches in an open (non-blinded) randomized controlled trial conducted in three Spanish worksites. Intervention participants (115 people) were graded by Fagerstrom score and treated with appropriate levels of nicotine replacement therapy for up to 12 weeks. Progress, withdrawal symptoms and adverse events were monitored over the 12-month trial period. Control group smokers (103 people) received brief, sporadic and unstructured advice, usually at their annual occupational health check.

Noor 2011, set in two Malaysian towns, offered a herbal compound (Viva QS) or placebo tablets to male smokers employed in 11 worksites and attending a mobile smoking cessation clinic. Participants were contacted by phone at two and four weeks, to assess progress and adverse events, and were given brief counselling. Outcomes were 7-day point prevalence and continuous abstinence from weeks 4 to 24, verified by expired CO. All participants, whether claiming abstinence or not, were checked face-to-face at 24 weeks. Fifty-four urine samples for cotinine were collected at week 24, but not analysed.

5. Social support for not smoking

Two studies evaluated social support as an increment to other cessation strategies (Malott 1984; Glasgow 1986). Social support, in this context, refers to the support of a 'significant other', for example a spouse, a workmate or a close friend.

Malott 1984 randomly assigned 24 smokers to controlled smoking or a controlled smoking plus partner support intervention. Both studies defined smoking reduction as one of their outcomes, targeting nicotine content (brand smoked), number of cigarettes smoked daily, and percentage of each cigarette smoked. Participants could choose either cessation or reduction as their desired outcome. The participation rate was not reported.

Glasgow 1986 recruited 29 smokers who were assigned to small groups and were then randomly allocated to a basic programme or basic programme plus social support. The participation rate was not reported.

GROUP 2: INTERVENTIONS AIMED AT THE WORKSITE AS A WHOLE

6. Environmental support for not smoking

We found three studies that reported environmental or institutional support programmes (Dawley 1991; Erfurt 1991; Hymowitz 1991). Tanaka 2006 also included environmental components, as one part of a complex intervention programme (see Comprehensive programmes for details).

Dawley 1991 evaluated a small study of workplace smoking control in two comparable oil refineries. One company was randomly assigned to an environmental programme of smoking control, discouragement, and cessation, while the other company received only a smoking cessation programme. Humorous anti-smoking posters emphasizing the benefits of quitting smoking were distributed throughout the intervention workplace and were changed every two weeks. Three weeks after the initiation of the smoking discouragement programme at one refinery, a group smoking cessation programme was begun at both plants. The participation rate was not reported.

Erfurt 1991 compared the effects of four interventions: (1) wellness screening, (2) wellness screening plus health education, (3) 1 and 2, plus follow-up counselling, and (4) 1, 2 and 3 plus peer support groups, buddy systems, health promotion classes, and plant-wide activities.

Hymowitz 1991 evaluated the effect of an enriched environment on the impact of a group quit-smoking programme in six workplaces. Two hundred and fifty-two smokers participated in the group quit smoking programmes; 131 at the full programme sites (group plus physician counselling plus workplace health promotion) and 121 at the group-only sites (group cessation programme). The participation rate was not reported.

7. Incentives

We found six studies of incentives with comparison groups and quit rates (Rand 1989; Windsor 1988; Glasgow 1993; Gomel 1993a; Hennrikus 2002; Volpp 2009). A number of other included studies (Klesges 1987; DePaul 1989; DePaul 1994; Sutton 1988a to Sutton 1988d; Tanaka 2006) used incentives as an aid to cessation or reduction, but not as the intervention being tested.

Rand 1989 examined the relative contribution of a contingent payment (up to USD 200) and workplace CO monitoring to the long-term maintenance of smoking abstinence. Forty-seven hospital employees who had abstained from smoking for five days were randomly assigned to one of three follow-up groups: contingent payment and frequent monitoring (n = 17), non-contingent payment with frequent monitoring (n = 16), or contingent payment with infrequent monitoring (n = 14).

Windsor 1988 studied the incremental effectiveness of skills training with social support enhancement and monetary incentives to a self-help manual. The participants were randomized to four groups in a two-by-two factorial pre-test/post-test design. The monetary incentive was a USD 25 payment to the employee after six weeks of abstinence. An additional USD 25 incentive was awarded at the end of six months abstinence.

Glasgow 1993 evaluated the impact of a year-long incentive-based workplace cessation programme (the HIP program). Nineteen workplaces were randomized to incentive or no-incentive conditions. Smokers were paid USD 10 each time they were confirmed abstinent by CO validation at monthly meetings over the year-long programme. In addition, each month at each workplace abstinent smokers were also eligible to win a lottery prize (which ranged from USD 5 to USD 20) and grand prize lotteries during the final month of the programme. All identified smokers in the workplace were considered as participants for the study, whether or not they participated in the intervention. Analyses were conducted at both the workplace and individual level and using both self-reported and biochemically validated cessation as endpoints. There was a participation rate of 23% in the incentive group.

Gomel 1993a, in a cluster-randomized study of 28 Australian ambulance stations, included an incentives component in its four-way comparison study to reduce cardiovascular risk factors. This trial is described above, under the individual counselling section.

The SUCCESS Project (Hennrikus 2002) compared three programme options (telephone counselling, group sessions, or a choice of either), each offered with and without incentives for recruitment and cessation. Four workplaces were assigned to each of the six options, and were surveyed at baseline, and again at 12 and 24 months. Incentive site smokers were paid for signing up to a programme (USD 10), for completing it (USD 20) and for 30 days abstinence (USD 20). Successful quitters were entered into a prize draw, to win up to USD 500. A sample of quitters at 24 months were also paid USD 25 if they supplied saliva for cotinine measurement.

Volpp 2009, set in a multinational company in the US, randomized smokers to information about local smoking cessation services versus the same information combined with stepped financial rewards for completing a smoking cessation course and for sustained cessation. Up to USD 750 were available to each intervention smoker for long-term (12-month) cessation biochemically confirmed. Participants were also rewarded for completing a smoking cessation course, for complying with assessments and for supplying confirmatory samples. The primary outcome was validated abstinence at 12 or 18 months (depending on earlier success). Assessments were conducted and rewards given some months after completion of the cessation programme.

8. Comprehensive programmes

We classify these trials into two groups:
(a) Programmes which used a combination of types of intervention to support the primary aim of the trial, i.e. to quit smoking.
(b) Programmes which used a mix of interventions to reduce a number of different high-risk behaviours, including smoking.

a) Multiple intervention smoking cessation programmes

We found seven trials which have smoking cessation as their primary or only outcome, but use a combination of interventions to address it (DePaul 1987; Willemsen 1998; DePaul 1989; Sorensen 1993; Shimizu 1999; Tanaka 2006; Okechukwu 2009).

DePaul 1987 randomized workplaces to self-help materials in conjunction with televised cessation programmes versus the same materials and programmes plus group or individual counselling at the workplace.

In DePaul 1989, the basic design was as for DePaul 1987, but enhanced with monthly booster sessions, and with successful quitters and up to five of their family and co-workers entered in a lottery at the end of the intervention period and at one-year follow-up.

Sorensen 1993 examined the effectiveness of a multi-component smoking cessation programme. The three-month intervention included consultation for employers on the adoption of a non-smoking policy (90-minute consultation), training for nonsmokers (a one-hour class) to provide assistance to smokers attempting to quit, and cessation classes for smokers (three one-hour behavioural cessation classes). Eight workplaces were randomized to two groups (intervention/no intervention) with one and two post-tests. Although the workplace was the unit of randomization, analyses were conducted using the individual as the unit of analysis. The participation rate was reported as 12% of smokers and 3.7% of nonsmokers. The attrition rate was not reported. No data were available for individual smoking cessation.

A Dutch study (Willemsen 1998) compared a comprehensive smoking cessation intervention of self-help manuals, group courses, a mass media campaign, and smoking policies with a minimal intervention of self-help manuals only. Eight workplaces (four matched pairs) participated in the study. The 'bogus pipeline' procedure was used to improve the validity of self reports of smoking status. This means that subjects are informed that their self reports can be biochemically verified, although the test is not necessarily performed. Respondents who claimed they were nonsmokers at the 14-month follow-up were asked to co-operate with biochemical validation of their smoking status.

A Japanese study (Shimizu 1999), available only as an abstract, examined the effectiveness of a multicomponent smoking cessation programme (intensive education, group lectures and individual counselling) compared to a waiting-list control group of smokers. The participation rate was not reported.

The HIPOP-OHP Study (Tanaka 2006) was a Japanese multicomponent intervention to reduce cardiovascular risk factors, including smoking, in six intervention sites matched to six control sites. The study concentrated mostly on blue-collar workers. The six-week cessation programme was offered five times over 36 months, and included information brochures on stages of change, four counselling sessions and NRT if requested. It was integrated with an intra-site publicity campaign (posters, newsletters, web site), designation of smoking areas, and an award for successful abstainers. Participants were assessed at 12, 24, and 36 months. The participation rate was 9% of smokers across the six sites.

Okechukwu 2009 targeted apprentices in the US building trades, with a four-month multi-pronged programme based on group counselling, supplemented by free NRT, self-help materials and environmental cues (posters, support materials). The smoking cessation component was integrated with training in work-related toxic hazards. The outcome was self-reported abstinence at least six months from the end of the intervention.

b) Multiple-outcome comprehensive workplace programmes

Thirteen studies evaluated multiple-outcome workplace programmes, i.e. targeting several health indicators, including smoking, for risk reduction (Kornitzer 1980; Shi 1992; Glasgow 1995; Sorensen 1996; Sorensen 1998; Emmons 1999; Nilsson 2001; Campbell 2002; Sorensen 2002; Sorensen 2007; Bergstrom 2008; Prochaska 2008; Milani 2009).

In the Belgian Heart Disease Prevention Project, Kornitzer 1980 cluster-randomized 30 paired Belgian factories to intervention or control conditions, with all male workers aged 40 to 59 eligible to take part. All intervention participants were screened for cardiovascular risk factors (blood pressure, serum cholesterol, weight, smoking and physical activity), and were given written advice to reduce their risks. The screening results were also passed on to participants' family and workplace doctors. The two deciles with the highest risk score were ranked as the high risk group, and additionally received six-monthly physician advice and testing. At the environmental level, anti-smoking posters were regularly displayed, and each intervention factory held a conference on the dangers of tobacco use. A five per cent sample of the intervention group were re-assessed annually. In the 15 control factories a random 10% sample were fully assessed at baseline, and then followed throughout the trial. Within that group a 20% high-risk group was identified and compared throughout with their intervention counterparts. The participation rate was 83.7% (n = 16,230).

The HealthWise Stepped Intervention Study (Shi 1992) allocated nine North Californian worksites belonging to Pacific Gas & Electric to four intervention levels. The seven sites allocated to levels 1 to 3 were randomly assigned, while the two smallest sites were allocated to Intervention level 4, in order to minimize the running costs of the trial. The trial lacked a no-treatment control site. The interventions ranged incrementally from Health Risk Assessments (HRAs) at the start and finish of the trial with a bimonthly health newsletter at Level 1, through the addition of a Health Resource Centre and self-care books at Level 2 sites, behavioural workshops and a social support team at Level 3, to an environmental smoking policy and a case management programme for the high-risk group (the 15% with the highest overall risk score) at Level 4. Outcomes were measured by cross-sectional HRAs at baseline and at two-year follow-up, and included smoking, drinking and speeding. The participation rate was 69% at baseline and 48% at follow-up.

The 'Take Heart' study (Glasgow 1995) evaluated the short-term effects of a low-intensity heart disease risk reduction programme, targeting smoking, dietary intake and cholesterol. Twenty-six workplaces with between 125 and 750 employees were randomly assigned to early or delayed intervention. Early intervention consisted of an 18-month multi-faceted programme that featured an employee steering committee and a menu approach to intervention activities tailored to each site.

The Working Well Trial (Sorensen 1996) used a randomized matched-pair design, with the workplace as the unit of assignment and analysis in 108 workplaces, with an average of 316 workers per site. The intervention targeted individuals and the workplace environment, and included dietary habits (all four study centres) as well as smoking (three of the four centres). Each centre also addressed one additional risk factor; these included occupational exposure to carcinogens, exercise, cancer screening, and smokeless tobacco.

Nested within the Working Well Trial, and based at the Massachusets study centre, was the WellWorks Study (Sorensen 1998), a randomized matched-pair trial in 24 workplaces. The two-year intervention, aimed at changing dietary and smoking habits, integrated health promotion and health protection through joint worker-management participation in programme planning and implementation, consultation on workplace changes, and educational programmes targeting health behaviour change, including smoking cessation. This study particularly addressed differences in behaviour change between white-collar and blue-collar workers.

Another study within the Working Well Trial was the Working Healthy Project (Emmons 1999). The Brown University study centre developed an extended programme within its 26 worksites (reduced eventually to 22), similar in aims and scope to the parent trial but including physical activity as a target objective, and following a cohort rather than assessment by cross-sectional surveys. The control sites received a minimal self-help programme of two smoking cessation courses and one each of nutrition and exercise, for those sites that wished to implement them.

A Swedish study (Nilsson 2001) reported the effects of a long-term comprehensive programme of lifestyle interventions, including smoking cessation, to reduce risk factors for cardiovascular disease. This randomized controlled trial for at-risk public sector employees also targeted body mass index, diastolic blood pressure, heart rate, low-density lipoprotein and cholesterol. The intervention group received individual counselling as well as 16 annual group sessions, using lectures, discussions, videos and outdoor activities; the control group received standard oral and written advice about cardiovascular risk reduction at the beginning of the trial, and nothing subsequently. Smoking point prevalence was assessed at 12- and at 18-months follow-up.

The Health Works for Women trial (Campbell 2002) developed a two-pronged approach to helping rural blue-collar women workers to improve their diet and physical activity levels, and to stop smoking. The programme was a combination of tailored 'magazines' at baseline and at six months, personalized for the characteristics and preferences of each participant, and social support at work from volunteer 'natural helpers'. The smoking intervention was incompletely delivered, however, as no lay helpers were willing to be trained to deliver the personal support. The control group received a minimal intervention (one personalized magazine) at six months, with no offer of social support. Randomization was by worksite. The participation rate was 73% at baseline.

Based on the WellWorks Study, WellWorks-2 (Sorensen 2002) was a block-randomized controlled trial of 15 workplaces, all handling hazardous chemicals. The intervention and aims of the study were very similar to the original WellWorks Project, being primarily health promotion and protection, but follow-up was only to six months. Like its parent project, WellWorks-2 targeted differences between white- and blue-collar workers, and concentrated on smoking and nutrition; an additional outcome of interest in this study was changes in perceived hazard exposure.

The Tools for Health study (Sorensen 2007) targeted American construction workers, on the basis that they represented a transient population who tended not to benefit from workplace occupational health provision. Six hundred and seventy-four workers, contacted through their trade union, completed a baseline survey on their smoking and their consumption of fruit and vegetables. The intervention consisted of tailored phone-based counselling (up to four calls over three months), mailed tailored feedback, six targeted mailings of educational materials, and NRT for those who requested it. At six months, 582 participants (including 188 smokers) completed the follow-up survey, giving an attrition rate of 13.6%.

Another Swedish study (Bergstrom 2008) allocated four companies in the paper, steel and truck manufacturing industries to a 3½-year comprehensive lifestyle programme to reduce risks of COPD, asthma and cardiovascular disease, and to target neck and back pain, alcohol, and absenteeism. The whole programme was offered three times over the course of the study. 'High-risk' individuals were offered inpatient rehabilitation courses based on behavioural approaches, while those deemed to be at moderate risk were given smoking cessation information and the offer of NRT by medical staff at the occupational health service. A 'reference' company acted as the control. Evaluation became problematic, as individual companies often set up their own health promotion activities, including 'stop smoking' support groups.

Prochaska 2008 aimed to compare the effect of three approaches (motivational interviewing, an online transtheoretical model (Prochange Lifestyle Management Programs), and a health risk intervention (HRI)) on four risk factors (inactivity, BMI, stress and smoking) in a worksite sample. We focus here on the smoking interventions, and compare the HRI-alone arm with the HRI plus motivational interviewing arm. The outcome was progression through the stages of change, but also reported six-month quit rates, although without end-of-study denominators.

Milani 2009 was a six-month comprehensive cardiovascular risk reduction programme in New Orleans, USA, targeting nutrition, smoking, and physical activity in employees and their spouses. The basis for inclusion was coverage by employer-sponsored healthcare insurance. Smoking was addressed in the intervention site by referral to a group counselling programme for smoking cessation. Participants who achieved milestones were rewarded with extra vacation days and "other job-related perks". Outcomes were assessed at one year, including any cost savings to the company.

Risk of bias in included studies

A summary of the 'Risk of bias' assessments is given in Figure 1.

Figure 1.

Risk of bias summary: review authors' judgements about each risk of bias item for each included study. Empty cells are for multiple studies within a single study report.

Some randomized studies aim to intervene with the workplace as a whole. They use a cluster-randomized design, allocating entire workplaces to conditions. Such studies should be analysed at the level of the cluster rather than the individual. When workplaces are the unit of allocation, but results are presented for individual quitters, the assumption that outcomes are independent is violated, since people in the same site may be more like one another than expected by chance. If the analysis ignores the clustering, the confidence intervals are likely to be too narrow (Bland 1997). The effect is greater if there are a small number of large clusters. Cluster-randomized studies with individual outcomes also present problems related to the choice of an appropriate denominator. The number of smokers who attend group meetings or use self-help materials is considerably smaller than the total number of smokers in a workplace. In cluster-randomized studies the denominator chosen for the analysis may be all smokers, smokers who express interest in treatment, or those who attend sessions. If the intervention involves individual cessation treatment, then trials focus on the outcome in the group of attenders. If the intervention includes other changes to the workplace environment, for example the introduction of restrictions on smoking, it is reasonable to assess the impact on the smoking workforce as a whole.

Eleven of the included studies (19%) reported randomization procedures in sufficient detail to be rated as adequate for their attempts to control selection bias. The majority of included studies (67%) either did not describe how randomization was performed or reported in insufficient detail to determine whether a satisfactory attempt to control selection bias had been made. Eight studies (14%) either failed to randomize appropriately or did not use a randomized trial design at all. In two studies (Sutton 1987; Sutton 1988e) a few control group subjects were allowed to move into the intervention group. One study (Li 1984) modified its randomization procedure partway through the study and was also obliged to reconstitute its experimental and control groups to accommodate physicians who did not comply with the protocol; Shi 1992 and Gomel 1993a allocated smaller or fewer worksites to the most expensive interventions in order to keep trial costs down. Gomel 1993a also reported some level of contamination between conditions as staff moved from station to station. Schröter 2006 compromised the distinction between the experimental and control group interventions, by applying 'rescue' relapse prevention techniques to members of the standard behavioural group when necessary. Prochaska 2008 reported six-month quit rates, but without the relevant denominators. Okechukwu 2009 warned that there may have been contamination between intervention and control cohorts, since randomization was by the union training base but apprentices from different bases could sometimes have worked together on the same worksites. Hishida 2010 reported that unexpectedly high cessation rates in the control group may have been associated with concurrent health promotion legislation to prevent passive smoking in the workplace.

Two Japanese studies (Shimizu 1999; Terazawa 2001) are included on the basis of data derived from the abstracts alone.

The 'gold standard' outcome for smoking cessation studies is biochemical validation of self-reported cessation (i.e. testing of saliva, blood, urine samples or exhaled breath for evidence of recent smoking). This generally results in lower rates of cessation, due not only to people misreporting their smoking, but also to relapsing, or refusing to provide samples for other reasons. Using validation may not change the relative effect of the intervention, since similar levels of misreporting are likely to be seen in the control condition as well, unless no intervention at all is provided to the control. Of the 55 studies in which intervention was provided to individuals, 41 (66%) used some form or combination of biochemical verification procedures for at least one follow-up point. These included butt counts, carbon monoxide ((CO) in 47% of the included studies), salivary thiocyanate and urinary, blood or salivary cotinine.

In assessing the potential impact of workplace interventions it is important to know the proportion of smokers who can be recruited to different types of intervention, whilst recognizing that some barriers to recruitment to trials may not be relevant to real settings. In some of the studies included here the use of a workplace population would appear to have been largely a matter of convenience for ease of recruitment. These studies have typically not reported on the proportion of the smoking workforce who participated. Where studies have calculated the participation rate we have recorded this in the Characteristics of included studies table. The participation rates in the studies included here ranged from 9% to 88%.

GROUP 1: INTERVENTIONS AIMED AT THE INDIVIDUAL TO PROMOTE SMOKING CESSATION

1. Intensive behavioural interventions: GROUPS

Only two of this group of 10 trials described the method of randomization in sufficient detail to exclude the possibility of allocation bias: in Omenn 1988 allocation was based on randomized assignment lists, while Razavi 1999 used random numbers concealed by a label. Four studies (Klesges 1987; DePaul 1994; Mayer 2010; Mishra 2010) used cluster randomization, and Gunes 2007 assembled matched cohorts of intervention and control participants, based on shifts worked, i.e. quasi-cluster-randomized. All of the trials except Schröter 2006, and Gunes 2007 used biochemical validation of self-reported smoking status. Two studies (Omenn 1988; DePaul 1994) used saliva cotinine, one study (Frank 1986) used saliva thiocyanate and one (Klesges 1987) used both saliva thiocyanate and expired air carbon monoxide. Two studies (Glasgow 1984; Mishra 2010) used expired air CO alone, and two studies (Razavi 1999; Mayer 2010) used a combination of expired CO and urinary cotinine.

2. Intensive behavioural interventions: INDIVIDUAL COUNSELLING

Only two of the eight studies in this group (Kadowaki 2000; Groeneveld 2011) adequately described the method of randomization. Three trials (Cambien 1981; Gomel 1993a; Lang 2000) used cluster randomization. Five studies used CO assessment for validation of self-reported cessation, with Lang 2000 using partial validation, as several workplace physicians had no access to a carbon monoxide monitor. Gomel 1993a used serum cotinine to validate smoking status at all assessment points, and Windsor 1988 used salivary cotinine testing. Only Groeneveld 2011 relied upon self report, without any biochemical validation.

3. Self-help interventions

Among this group of six studies, none described the method of randomization. All except Hishida 2010 validated their cessation rates, the Sutton studies with expired air CO, and Omenn 1988 with salivary cotinine.

4. Pharmacological therapy

Three studies described adequate randomization procedures, for a placebo-controlled double-blind trial (Kornitzer 1995; Noor 2011) and an open-label randomized controlled trial (Rodriguez 2003). The remaining two studies allowed movement between the intervention and control groups (Sutton 1987; Sutton 1988e). All five studies validated self reports of cessation, using expired air CO to verify smoking status. Noor 2011 collected end-of-trial cotinine samples from all participants, whether abstinent or not, but failed to analyse the urine samples because of technical problems at the laboratory.

5. Social support for not smoking

Neither study (Malott 1984; Glasgow 1986) gave randomization details or participation rates. Self-reported cessation was validated in both studies using expired air CO and quantity of cigarette butts. The Glasgow study also monitored saliva cotinine.

GROUP 2: INTERVENTIONS AIMED AT THE WORKPLACE AS A WHOLE:

6. Environmental support for not smoking

Three of the four studies in this group employed a clustered design, with Tanaka 2006 allocating sites non-randomly to intervention or control in a matched-pair design. Two of the cluster-randomized trials (Dawley 1991; Hymowitz 1991) analysed by individual, while the third (Erfurt 1991) used the workplace as the unit of analysis. There was no biochemical validation of self-reported cessation in Erfurt 1991 or Tanaka 2006. Dawley 1991 reported validation by urinary cotinine and Hymowitz 1991 by expired air CO.

7. Incentives

Details of Gomel 1993a are reported under the Individual Counselling heading.
Windsor 1988 described randomization using a computer-generated assignment system in numbered envelopes. Glasgow 1993 was described as cluster-randomized with both the workplace and the individual used as the units of analysis. Rand 1989 gave no details of randomization. The SUCCESS Project (Hennrikus 2002) was described as a 3x2 factorial study, with workplaces randomly assigned to the six treatment options, but stratified by gender and education level. No details of randomization were offered. Volpp 2009 randomized in permuted blocks of four, stratified by site, income and level of smoking (more or less than 40 per day). Assignments were concealed in this trial until after allocation, but not thereafter. All six studies reported biochemical validation, using saliva thiocyanate (Windsor 1988; Hennrikus 2002; Volpp 2009), serum cotinine (Gomel 1993a), urine if on NRT (Volpp 2009), or carbon monoxide (Rand 1989) and carbon monoxide plus cotinine (Glasgow 1993).

8. Comprehensive approach

No details of randomization were given, apart from Okechukwu 2009, who used a random number generator. Bergstrom 2008, Tanaka 2006 and Willemsen 1998 allocated the worksites non-randomly to intervention or control status. Fourteen of the 20 studies employed a cluster-randomized design, while Nilsson 2001 aggregated its participants from four public sector workplaces within the same district. Non-validated self-reported smoking cessation was recorded in 14 studies, partial or complete saliva cotinine validation in two studies (DePaul 1987; DePaul 1989), and CO in Shimizu 1999 and Campbell 2002. Sorensen 1993 at six months and Willemsen 1998 at four months collected saliva cotinines, but did not test them (the 'bogus pipeline' principle). Willemsen 1998 did, however, collect and test cotinine samples for 52% of self-reported quitters at the 14-month follow-up.

Effects of interventions

See: Summary of findings for the main comparison Smoking cessation interventions for the workplace

Smoking cessation/reduction

For this update, we have conducted meta-analyses of the main classes of intervention. Where there was more than one intervention arm, we have compared the control group (minimal or no intervention) with the next simplest treatment. Although this may occasionally underestimate the trial's true efficacy over multiple interventions, we avoid the risks of overstating the effect of the treatment or of tipping a result into significance by forcing a binary comparison that does not reflect the true findings of the trial. Studies treated selectively in this way include DePaul 1994, Erfurt 1991, Glasgow 1984, Kornitzer 1995, Omenn 1988, Rand 1989, Razavi 1999, Sutton 1988a, Sutton 1988b, Sutton 1988c, Sutton 1988d, Windsor 1988, Prochaska 2008 and Mishra 2010. Analysable data were not available for Hennrikus 2002 (incentives, Analysis 2.2), for Sorensen 1993 (multiple intervention programmes for smoking cessation; Analysis 2.3) or for 10 of the 13 comprehensive programme trials targeting multiple risk factors (therefore not meta-analysed).

We have also produced a Results table (Analysis 3.1), which gives details of types of participants, follow-up, smoking outcomes and validation of cessation.

GROUP I: INTERVENTIONS AIMED AT THE INDIVIDUAL TO PROMOTE SMOKING CESSATION
1. Intensive behavioural intervention: GROUP COUNSELLING

Eight trials (1309 participants) of worksite-based group behavioural therapy interventions for smoking cessation demonstrated a benefit for the counselling programmes, with an odds ratio (OR) of 1.71 (95% confidence interval (CI) 1.05 to 2.80; Analysis 1.1.1). There was no statistical heterogeneity (I² = 0%).

Within this category, two trials of relapse prevention using group-based therapy (484 participants) found no benefit for the programmes: OR 1.15 (95% CI 0.80 to 1.65); Analysis 1.1.2.

Glasgow 1984 showed that at six months one-third of participants in the gradual condition were abstinent compared to no participants in the abrupt condition. However, in this small sample the result was not statistically significant. This study also targeted smoking reduction as a valid outcome, and 47% of participants stated that they wished to reduce their consumption. Reducers were found to have been successful for each of the target behaviours as they addressed them, without compensatory increases in the other two behaviours. Achieved reductions were statistically significant (P values from 0.001 to < 0.02). Mean reduction in nicotine content was 50%, in percentage of each cigarette smoked 34% and in number of cigarettes smoked 28%. Carbon monoxide (CO) levels were 28% lower on average, suggesting that participants were not compensating for the behavioural changes. All but one participant improved on at least two measures, and 46% on all four variables. At six-month follow-up, reducers maintained all the changes except for percentage of the cigarette smoked, with both abrupt and gradual plus feedback participants relapsing on this measure (P < 0.05).

Frank 1986, testing combinations of behavioural support and hypnotic sessions, showed no long-term differences between any treatment variants.

Klesges 1987, testing both a relapse prevention component and a competition in a factorial design, failed to detect evidence for a long-term benefit of either. At the immediate post-test, the competition intervention resulted in higher quit rates (39% versus 16%, P < 0.004) but these differences were minimal at six months (12% versus 11%, NS). The six-month differences for relapse prevention were in the expected direction but not statistically significant (15% versus 8%), although the competition appeared to increase short-term quit rates.

Omenn 1988 showed non-significant trends towards higher quit rates for groups than for self-help controls. The three Group arms achieved 12-month validated quit rates of 16% for the multiple component arm, 18% for the relapse prevention arm and 8% for the minimal treatment arm (NS).

In DePaul 1994 at 12 months, the self-help participants achieved a sustained abstinence rate of 5.1%, the incentives participants 11%, and the group participants 31.2% (P < 0.01).

Schröter 2006 found that participants in the standard behavioural (SB) programme were more successful than those who received relapse prevention (RP) support (21.1% continuously abstinent at 12 months versus 12.2%). They speculated that this unexpected finding might be attributable to the emphasis in the RP group on the likelihood of failure, but also noted that SB participants had received relapse prevention 'rescue' support when necessary, which may have compromised the separation between the two interventions.

Gunes 2007 reported a non-significant difference in the six-month quit rate between the intervention and control groups (6% versus 2%, P = 0.14). The primary outcome of interest for this study was movement through stages of change, and for this measure the intervention group achieved significantly lower numbers in 'pre-contemplation' and higher numbers in the 'preparation' stages at six months, but this did not translate into higher quit rates within the time scale of the trial.

Mishra 2010 demonstrated a benefit for counselling and focus groups over self-help materials alone at 12 months, with an intervention quit rate of 20% compared to 6% in the control group (P = 0.03). The two incrementally more intensive arms (+ individual counselling, and + bupropion if wished) achieved similar results, with 12-month quit rates of 19% (P = 0.06) and 20% (P = 0.03) respectively.

For the two relapse prevention studies, Mayer 2010 did not detect an advantage at nine months for the proactive phone counselling (57.5% remained quit) over the worksite-based group programme (61.7% remained quit, P = 0.552). Predictors of higher abstinence included a lower BSI-GSI score, lower levels of urinary cotinine, and having to pay EUR 50 for the programme.

The Belgian relapse prevention study (Razavi 1999) found differences between psychologist-supported quitters (43.7% still abstinent at 12 months), ex-smoker-supported quitters (37.5%) and no formal support quitters (35.5%), but these did not reach statistical significance.

2. Intensive behavioural interventions: INDIVIDUAL COUNSELLING

Eight trials (3516 participants) of worksite-based individual counselling interventions demonstrated a benefit for the counselling programmes, with an OR of 1.96 (95% CI 1.51 to 2.54; Analysis 1.2). There was minimal statistical heterogeneity (I² = 24%).

Cambien 1981 found that at two-year follow up 21.4% (65/304) of smokers in the intervention group had quit, compared with 13.4% (41/306) in the control group. Although the descriptive forest plot suggests that this result was statistically significant, the authors report that it was not. The result does not take account of the 195 participants lost to follow-up, and the authors observe that those lost to follow-up from the intervention group were significantly heavier smokers than the follow-up attenders (P < 0.01) or the control participants.

Li 1984 found that at 11 months smokers given behavioural counselling from a physician were more likely to remain abstinent (8.4%) than those with a minimal warning (3.6%, P < 0.05). Prolonged abstinence rates did not differ between participants with abnormal lung function tests (3.7%) and normal lung function tests (5.9%).

Windsor 1988: As the two incentive arms of the trial did not detect any significant benefit for the payment schemes, the authors collapsed the incentive and no-incentive groups together in the analysis to test the efficacy of adding counselling and social support to self-help materials. This comparison yielded a cessation rate of 5.8% (11/190) at 12 months for the combined self-help groups, compared with 14.4% (27/188) for the self help with counselling and social support combined groups (P < 0.001).

Gomel 1993a did not find significant differences in continuous abstinence rates between any of the four groups (HRA, RFE, BC and BCI) at six or 12 months. However, when the authors pooled the HRA group with RFE (n = 68 smokers) and BC group with BCI (n = 60 smokers) to test the efficacy of the counselling component, they detected statistically significant differences in abstinence rates. At six months, the combined HRA/RFE group had a continuous abstinence rate of 1%, compared with 10% for the BC/BCI pooled group (Fisher's Exact Test P = 0.05); 12-month rates were 0% and 7% respectively (P = 0.05). The authors report that contamination between the intervention groups and low participation rates among the RFE stations meant that the effect size of the whole trial may have been compromised.

Kadowaki 2000 found cessation rates of 12.9% and 3.1% in the intervention and control groups respectively (P = 0.003). Among those who succeeded in quitting 48.6% maintained cessation at 18-month follow-up. Overall the cessation rate was 8.4% after 22 months and the prevalence of male smokers had decreased from 62.9 to 56.7% (P = 0.038).

Lang 2000 found point prevalence quit rates of 18.4% in the intensive group compared to 13.5% in the minimal intervention group at one year (P = 0.03). Self-reported sustained cessation of six months and more was reported in 6.1% of the intervention group compared with 4.6% of the comparison group (P = 0.26).

Terazawa 2001 detected a point prevalence cessation rate of 11.1% (13/117) at 12 months in the intervention group, compared with 1.8% (2/111) in the control group. Twelve-month continuous abstinence rates were 6.8% (8/117) and 0.9% (1/111) respectively (Fisher's Exact 2-tailed Test P = 0.04 [our calculation]). Only 25 of the 117 counselled smokers in the intervention group agreed to make a quit attempt and would therefore have received the four follow-up phone calls.

The HIPOP-OHP study (Tanaka 2006) detected a steady rise in quit rates in both the intervention and control worksites over the 36-month assessment period. They report final quit rates of 12.1% in the intervention sites versus 9.4% for the controls (P = 0.021), but this is based only on those who responded at both baseline and at final follow-up. An intention-to-treat analysis yields quit rates of 8.9% and 7.0% respectively (P = 0.046 [our calculation]).

Groeneveld 2011 found that a statistically significant benefit at six months (31.3% versus 13.4%) was not sustained to 12 months (23.7% versus 19.5%; P = 0.45). The intervention was more successful in older participants (> 45 years) at both time points.

3. Self-help programmes

Six trials (1906 participants) of worksite-based self-help interventions demonstrated no clear benefit for the self-help programmes, with an OR of 1.16 (95% CI 0.74 to 1.82; Analysis 1.3). There was no statistical heterogeneity (I² = 0%).

Omenn 1988, discussed earlier in the group counselling section, reported that the self-help arms achieved 12-month validated cessation rates of 9% for the multiple component arm, 11% for the relapse prevention arm, and 6% for the minimal treatment arm (NS).

Video studies
The four studies of minimal video interventions with control groups (Sutton 1988a; Sutton 1988b; Sutton 1988c; Sutton 1988d) failed to detect a difference in validated abstinence rates between the video groups, although the second study (Sutton 1988b) detected a difference between the video groups and the non-participant group (P < 0.05). This study, however, included younger smokers who smoked more heavily than participants in the other three studies. Another finding of the first of the studies (Sutton 1988a) was of more smokers trying to stop in the intervention group than in the control group (P < 0.05), but in that study the 'control' video concerned seatbelts, whereas the 'control' videos in the other three studies all related in some way to tobacco.

Genotyping information studies

Hishida 2010 found a higher quit rate among the controls (baseline information, plus observation only, 8.0%) at 12 months than in the intervention group (baseline information, then genotyped, 5.8%; P = 0.34). Although the authors offer concurrent anti-smoking legislation as a possible confounder to account for this, it is not clear why that would have impacted the control group more heavily than the intervention group. Comparisons by genotype also detected no significant differences, with quit rates of 5.6% and 7.1% in the LS and SS (high-risk) groups respectively versus 4.9% (P = 0.723) in the LL (low-risk) group.

4. Pharmacological therapy

Five trials (1092 participants) of worksite-based pharmacological interventions demonstrated a benefit for the treatment programmes, with an OR of 1.98 (95% CI 1.26 to 3.11; Analysis 1.4). There was mild statistical heterogeneity (I² = 19%).

Sutton 1987 reported one-year continuous abstinence rates of 12% among those allocated to nicotine gum and 2% among the control group (no P value given). If an intention-to-treat analysis (i.e. based on all randomized participants) is performed on these data, the quit rate drops to 7.8% for the intervention group at 12 months.

Sutton 1988e reported validated one-year abstinence rates of 22% in those receiving nicotine gum compared with 2% in the control group (P < 0.001). An intention-to-treat analysis of these data would yield an intervention quit rate of 10.1% (8/79). The more rigorous 'complete' abstinence rates (i.e. no smoking of any kind up to follow-up assessment) are 6.3% (5/79) for the intervention group and 2.4% (2/82) for the controls.

In Kornitzer 1995 the three treatment groups (Group 1: active nicotine patch and active gum; Group 2: active nicotine patch and placebo gum; Group 3: placebo patch and placebo gum) achieved 12-month abstinence rates in Group 1, 2 and 3 of 18.1%, 12.7% and 13.3% respectively (P = 0.19). ORs comparing Groups 1 and 2 at 12 months (OR 1.47, CI 0.76 to 2.78, P = 0.125), and comparing Groups 2 and 3 (OR 0.96, no further details) were not significant. Time to relapse was longer in Group 1 compared with the other two groups (P = 0.04).

Rodriguez 2003 detected a 12-month CO-validated continuous abstinence rate of 20.2% (23/114) in the intervention group, compared with 8.7% (9/103) among the controls. This gave an OR of 2.58 (95% CI 1.13 to 5.90, P = 0.025). These results are based on an intention-to-treat analysis, except for one death in the intervention group.

Noor 2011 found a higher rate of continuous abstinence (weeks 4 to 24) in the intervention than in the control group; 25.3% versus 12.5%, P = 0.04. Although point prevalence abstinence was biochemically validated, the continuous abstinence rates were not.

5. Social support for not smoking

Two trials (53 participants) of worksite-based social support interventions demonstrated no benefit for the programmes, with an OR of 0.69 (95% CI 0.18 to 2.62; Analysis 1.5). There was no statistical heterogeneity (I² = 0%).

Two studies of social support (Malott 1984; Glasgow 1986) found no difference with the addition of this component to a basic programme of group counselling and support. Both studies also defined smoking reduction as an outcome of interest, in which participants could choose to attempt either complete cessation or reduction of smoking. In the earlier study (Malott 1984) the authors note that among non-abstainers, at six months follow-up the Controlled Smoking (CS) Group daily consumption of nicotine was 0.52 mg compared with Controlled Smoking + Partner Support (CS+PS) Group's consumption of 0.45 mg. Average number of cigarettes per day at six months follow-up was CS:21.5, compared with CS+PS: 20.1. In both conditions, participants relapsed on number of cigarettes smoked (P < 0.05). In addition, CS participants relapsed on nicotine content (P < 0.05), and CS+PS relapsed on percentage of cigarette smoked (P < 0.01). Neither group relapsed on CO levels, and non-abstinent smokers in both groups were smoking less at follow-up than they had been before treatment.

In Glasgow 1986 no differences in outcome were detected between the two groups of reducers (Basic Programme [BP] and Basic Programme + Social Support [BP+SS]). Both groups at six months had achieved reductions in nicotine (BP: 0.90 to 0.49; BP+SS: 0.78 to 0.49, P < 0.05 for both). Number of cigarettes per day was reduced in both groups (BP: 20.5 to 18.3; BP+SS: 27.7 to 24.4), but was statistically significantly higher than at immediate post-test. The same pattern applied to percentage of each cigarette smoked, although the BP+SS group six-month rate was still lower (P < 0.05) than pre-test levels (BP: 83.3 to 74.8; BP+SS: 89.0 to 81.2). Carbon monoxide levels followed the same pattern, while saliva thiocyanate levels were higher at six-month follow-up than at baseline. As with cessation, this study offered no evidence that social support enhanced sustained reduction.

GROUP 2: INTERVENTIONS AIMED AT THE WORKSITE AS A WHOLE
6. Environmental support for not smoking

Four trials (3851 participants) of worksite-based environmental support demonstrated no benefit for the environmental programmes, with an OR of 1.00 (95% CI 0.60 to 1.65; Analysis 2.1). There was no statistical heterogeneity (I² = 0%).

In Dawley 1991 at five months the abstinence rate at the environmental intervention site was twice that of the cessation-only site (43% versus 21%, no P value given).

Erfurt 1991 compared the effects of four interventions: (1) wellness screening; (2) wellness screening plus health education; (3) as 2, plus follow-up counselling; and (4) as 3, plus peer support groups, buddy systems, health promotion classes, and plant-wide activities. In each group there was a reduction in the prevalence of smoking over three years, and the smoking prevalence at three years was lower for interventions 3 and 4 compared with interventions 1 and 2 (P < 0.01), although this difference depended on combining the 1985 smokers with the then ex-smokers. Interventions 3 and 4 recorded slightly higher quit rates (20.3% and 18.9% respectively) than interventions 1 and 2 (17.1% and 17.6% respectively) among employees who were smoking at baseline, but the difference was not statistically significant, and may have been compromised by differences in baseline.

Hymowitz 1991 failed to detect an effect of environmental support. Twelve-month quit rates were 22% for physician counselling and group support alone, and 18% for the same support with an 'enriched milieu'.

Tanaka 2006 found that quit rates in both groups rose steadily over 36 months of follow-up. Six-month sustained abstinence at 36 months (ITT analysis) was 8.9% for the intervention sites versus 7.0% for the controls (P = 0.0467).

7. Incentives

Five trials (1928 participants) of worksite-based incentive interventions demonstrated a benefit for payment or reward schedules, with an OR of 1.60 (95% CI 1.12 to 2.30; Analysis 2.2). There was moderate statistical heterogeneity (I² = 43%). Hennrikus 2002 did not contribute any analysable data to this comparison.

Our analysis of the incentives trials demonstrates a benefit for rewards programmes over the control condition. However, a single study (Volpp 2009) contributed 37% of the weight and all of the statistical significance to this analysis; removing these data reduced the OR to 1.16 (95% CI 0.73 to 1.83). But despite this cautionary note, we observe that Volpp 2009 was the only study to conduct assessments and deliver rewards considerably after the cessation programmes, when success rates might have been expected to have dissipated. This was a large study conducted and reported to high standards, and delivering robust findings.

Windsor 1988 failed to detect an effect of monetary incentives on quit rates, with 6/95 achieving continuous cessation in the self-help group at 12 months compared with 5/95 in the self help plus incentives group. The corresponding rates for the counselling groups were 18/94 and 9/94. If anything, the incentive component appeared to have a negative impact.

Rand 1989 found that contingent payments delayed but did not necessarily prevent relapse to smoking. The study failed to detect an effect on relapse of monitoring and feedback of CO rates.

Glasgow 1993 failed to detect a difference between incentive and no-incentive conditions across 19 workplaces. There were no statistically significant differences in self-reported cessation rates at one year (12.9% for incentives versus 12% for control) or at two years (18% for incentives versus 15.5% for control).

The SUCCESS Project (Hennrikus 2002; not included in the meta-analysis) found that programme recruitment was higher in the incentive sites (22% vs 12%, P = 0.0054), but that this did not translate to higher cessation rates. Although the authors suggest that telephone counselling appeared to be at least as effective as group programmes, the two types of support seem to have been offered at different levels of intensity, with drop-outs from group programmes not followed up, while telephone counsellors routinely made ten contact attempts per session plus messages or letters to their participants.

Gomel 1993a failed to detect an effect of either individual or group incentives. Rewards appeared to have no effect, or possibly a negative impact, with 3/30 smokers continuously abstinent at 12 months in the BC (counselling only) group compared with 1/30 in the BCI (counselling plus incentives) group, but this difference did not achieve statistical significance. Other outcomes for this trial are covered under the Individual Counselling heading.

Volpp 2009 detected a statistically significant benefit of incentives over control conditions, with 15- or 18-month prolonged abstinence rates of 9.4% versus 3.6% (P = 0.0008) respectively.

The effectiveness of incentives and competitions as an aid to smoking cessation in any setting is covered in another Cochrane review (Cahill 2011).

8. Comprehensive programmes
(a) Multiple interventions for smoking cessation:

Six trials (5018 participants) demonstrated a benefit for comprehensive programmes aimed at smoking cessation, with an OR of 1.55 (95% CI 1.13 to 2.13; Analysis 2.3.1). There was some heterogeneity (I² = 30%). Sorensen 1993 did not contribute analysable data to this comparison.

The initial De Paul study (DePaul 1987) achieved 12-month sustained cessation rates of 6% for the group participants versus 2% for the self-help participants (NS), with both arms achieving a 19% point prevalence rate. It reported a non-significant trend towards higher quit rates for groups than for self-help controls.

Willemsen 1998 failed to detect an effect of a comprehensive programme. The six-month sustained abstinence rates were 8% in the comprehensive workplaces and 7% in the minimal-treatment workplaces. Among the medium to heavy smokers, prolonged abstinence rates were 9% for the comprehensive programme and 4% for the minimal programme.

At 12 months, point prevalence for the group participants in DePaul 1989 was 26%, compared with 16% for non-group participants (P < 0.06), with sustained abstinence rates of 11% and 3% respectively (P < 0.05).

Sorensen 1993 (not included in the meta-analysis) demonstrated that at six-month follow-up, 12% of smokers in the intervention group reported quitting, compared to 9% in the control group (P < 0.05), with cessation predicted by co-worker requests not to smoke.

A small study (Shimizu 1999) of a multicomponent programme including group and individual counselling did not detect a statistically significant difference, with quit rates of 19% in the intervention group and 7% in the control group.

Tanaka 2006 detected a six-month sustained abstinence rate at 36 months of 8.9% (self-reported) for the intervention sites versus 7.0% for the control sites (P = 0.0467). Quit rates in both groups rose steadily over the three-year course of outcome measurement.

Okechukwu 2009 found that a significantly higher one-month quit rate in the intervention group had dissipated to a non-significant difference by six months, at 9% versus 7.2% (P = 0.48). These results were not biochemically validated, in order to avoid any perceived association with 'drug-testing', and because such tests might have been confounded by work-related toxins.

(b) Comprehensive interventions targeting several risk factors, including smoking

Since only three trials (Glasgow 1995; Prochaska 2008; Milani 2009; 383 participants) of the 13 (> 78,000 participants) in this group offered data for meta-analysis, we decided against pooling these findings, as they are likely to be unrepresentative and misleading. We report the results here narratively, and in the Results Table Analysis 3.1.

Kornitzer 1980 detected a decline in smoking prevalence of 18.7% in the high-risk intervention group at two-year follow-up, compared with a 12.2% drop in the high-risk control group (P < 0.05). A five per cent sample of all the intervention participants demonstrated a prevalence decline of 12.5% over two years, which was very close to the 10% sample control group's decline of 12.6% (non-significant). The authors speculate that the lack of face-to-face counselling (available only to the high-risk intervention group) may have been a significant factor in the failure of the anti-smoking campaign. Stepwise multiple discriminant function analysis among the high-risk groups identified fewer cigarettes smoked at baseline, more previous quit attempts and the residential area of the country as significant predictors of quitting among the intervention group, and higher education and more previous quit attempts among the controls. The significant differences between intervention and control high-risk groups gradually disappeared over the subsequent four years of the study, due to a combination of less intensive intervention activity and a spontaneous rise in the control group's quit rate in line with secular trends.

The HealthWise Stepped Intervention Study (Shi 1992) noted a decline in smoking prevalence at two-year follow-up in all four intervention levels (nine worksites). Smoking reduced in Level 1 sites by 34%, from 18% to 12%, in Level 2 sites by 18%, from 17% to 14%, in Level 3 sites by 35%, from 24% to 15%, and in Level 4 sites by 44%, from 14% to 8%. All differences were statistically significant at P < 0.01 level, except for the Level 2 decline which was significant at the 0.1 level. Outcomes were measured by cross-sectional surveys rather than cohort analysis, with relatively low participation rates of 69% at baseline and 48% at follow-up.

The 'Take Heart' study (Glasgow 1995) reported that the early and delayed intervention groups did not differ on changes in smoking rates, dietary intake or cholesterol levels. Despite documented implementation of the intervention, there were no short-term improvements beyond secular trends also observed in control workplaces. Glasgow 1997 (an excluded study) also reported the results of 'Take Heart II' which was non-randomized but with a matched quasi-experimental study design similar to the first 'Take Heart' trial, plus updated menu and added guidance for employee steering committees and implementation. The authors reported that there were no statistically significant differences in smoking prevalence and smoking cessation between intervention and control workplaces.

The Working Well Trial (Sorensen 1996) reported a non-significant 1.53% difference between intervention and control workplaces in six-month smoking cessation rates. Smoking prevalence declined in intervention sites (from 24.5% to 21.2%) and in control sites (from 25.8% to 21.8%) (NS).

The WellWorks Study (Sorensen 1998) nested within the Working Well Trial, was a randomized controlled trial, with similar aims to its parent trial, but combining health promotion and health protection interventions, and also targeting outcome differences by job category. Six-month smoking abstinence rates were 15% in the intervention workplaces, and 9% in the control workplaces (P = 0.123). We have not used the first analyses for this study, published in 1996, since these did not include results from the control workplaces.

At three-year follow-up, the Working Healthy Project (Emmons 1999) did not detect significant differences between either the seven-day point prevalence quit rates (intervention 25.6% versus control 21.8%) or the six-month continuous abstinence quit rates (intervention 8.0% versus control 8.1%).

The Swedish trial of cardiovascular risk reduction (Nilsson 2001) detected a decline in smoking prevalence in the intervention group from 65% to 37% at 12 months, compared with a non-significant decline in the control group from 65% to 63%. Prevalence at 18 months was 40% for the intervention group and 59% for the control group, and this difference influenced the decrease in the mean risk score from 10.3 (standard deviation (SD) 1.5) to 9.0 (SD 2.2, P = 0.042).

The intervention arm of the Health Works for Women trial (Campbell 2002) had a higher smoking prevalence at baseline (30%) than the control arm (22%), but only 9% of the intervention participants (26% of the current smokers) chose to concentrate their efforts on quitting. Both groups reduced their prevalence rate by about 3% at 18-month follow-up. The intervention for smokers was incomplete, as no lay helpers were willing to be trained to support the smokers trying to quit. It is therefore not possible to draw any meaningful inferences from the lack of a detectable difference between the two arms of the trial.

The WellWorks-2 Trial (Sorensen 2002) did not detect a significant difference in point prevalence rates at six months between intervention and control workplaces (reductions of 4.1% and 1.6% respectively). Cohort analysis failed to detect an effect in overall quit rates between intervention (11.3%) and control workplaces (7.5%, OR 1.57, P = 0.17).

Sorensen 2007 detected a significant increase in the six-month quit rate in the intervention group compared with the controls (19% versus 8%, P = 0.03). This analysis was restricted to the 188 smokers who completed both the baseline and follow-up surveys, although the authors reported that an intention-to-treat (ITT) analysis also found a statistically significant benefit of the intervention. The ITT data were 19 quitters from 125 baseline smokers in the intervention group (15%), compared with 7 quitters from 106 baseline smokers in the control group (7%, P = 0.04).

Bergstrom 2008 evaluated a 3½-year comprehensive programme at ten time points, including smoking cessation support by the occupational health services for those assessed as being at moderate risk, and referral to inpatient rehabilitation or inpatient smoking cessation for those at high risk. All four intervention companies showed a decline in smoking prevalence compared with the reference (control) company; Companies 1, 2 and 4 demonstrated a statistically significant decline (-0.60 (P < 0.05), -0.92 (P < 0.01) and -0.45 (P < 0.05) respectively), while the decline in Company 3 (-0.09) was non-significant. Sensitivity analyses to assess white- and blue-collar workers separately found no meaningful differences between the subgroups.

The primary outcome for Prochaska 2008 was movement through the stages of change in response to three workplace interventions targeting inactivity, BMI, stress and smoking. The comparison of health risk intervention (HRI) alone versus HRI + motivational interviewing (MI) for smoking cessation indicated a non-significant benefit for the MI arm, with an abstinence rate at six months of 34.6% versus 16.7%. The third arm (HRI + transtheoretical model) achieved a rate of 21.1%. We were unable to establish the distribution of the 101 reported to be 'at criterion' at six months (i.e. deemed to be in the action stage, which for smoking was defined as achieving point prevalence abstinence). We have therefore applied an intention-to-treat principle, using the baseline smokers as the denominators for our assessment of success rates.

In a personal communication, Milani 2009 reported six-month point prevalence cessation rates of 18.2% (6/33) for the intervention group, and 0% (0/31) for the control group (P = 0.08). The primary outcome for this trial was cost savings to the employer of a systematic health promotion programme for their insured work force.

Economic analysis

There is limited literature on the costs of implementing workplace smoking control programmes. Only six of the studies identified for this review (Windsor 1988; DePaul 1989; Erfurt 1991; DePaul 1994; Tanaka 2006; Milani 2009) reported cost data. All except the Japanese HIPOP-OHP study were conducted in the USA.

Windsor 1988 found that material costs to deliver the programme plus lost employee time to participate produced a total programme cost of approximately USD 50 per employee. The cost to implement the programme for combined groups 1 (brief advice and self-help materials) and 3 (as 1 with monetary awards) was approximately USD 9500 (USD 50 x 190 per combined intervention group). The estimated savings to the University for Groups 1 and 3 with a 5.8% quit rate (9 employee quitters at USD 1000) was about USD 9000. From a cost-to-benefit ratio perspective the estimated savings observed from combined groups 2 (as 1 with self help, further counselling, buddy selection and contract) and 4 (as 2 with monetary rewards for cessation) was the same as for groups 1 and 3 (USD 9500). The observed quit rate of 15% (27 employee quitters at USD 1000) produced an estimated saving of approximately USD 27,000. The researchers suggested that reducing the estimated savings by 50% (for example, USD 500 per employee per year instead of USD 1000) still led to estimated savings of USD 13,500, 40% above the estimated cost of USD 9500. The cost-to-benefit ratio for the most effective methods (groups 2 and 4) was approximately 2 to 1.

DePaul 1989 showed that in the Group condition (media, self-help manuals, groups and incentives) 44 participants had quit at the 12-month follow-up and for the Non-group condition 26 had quit smoking. Incentives and supplies cost approximately USD 21,000 for the Group intervention, so each Group quitter cost USD 477. Supplies for the Non-group cost about USD 2000, so each quitter cost USD 77.

Erfurt 1991 found that the annual direct cost per employee for post-screening interventions was USD 2.97 for site 1 (control site), USD 17.68 for site 2 (health education), USD 30.96 for site 3 (health education plus follow-up counselling), and USD 38.31 for site 4 (health education, follow-up counselling plus plant organization for health promotion). For engaging employees into treatment or programme participation, sites 3 and 4 were approximately 10 times more cost-effective than site 2. Also, for reducing risks and relapse prevention, sites 3 and 4 were five to six times more cost-effective than site 2. At sites 3 and 4 the total direct cost per percentage of risks reduced and relapse prevented was less than one dollar (USD 0.67 and USD 0.74, respectively) per employee per year.

The last of the DePaul studies, DePaul 1994, summarized the cost implications of all three De Paul studies. The total cost for each intervention was Self-help USD 4717, Incentives USD 6992 and Group USD 26,867. Costs per quitter (12-month point prevalence to continuous quit rate) were Self-help USD 225 - 1179, Incentives USD 250 - 699 and Group USD 455 - 790. The cost of the programme offered to the public (50,000 self-help manuals and newspaper supplements) was USD 62,500. If 5% to 15% of the recipients of self-help materials could quit smoking, the cost would range from USD 8 to USD 25 per quitter. With the television series costing about USD 20,000, if only 5% of smokers who watched it managed to quit, the cost per quitter would be USD 3.

The HIPOP-OHP Study (Tanaka 2006) calculated that the intervention delivered 36.3 additional quitters, in a period when intervention and control sites all reported a steady rise in the cessation rate. Based on materials and opportunity costs, each quitter was estimated to have cost JPY 70,080 (95% CI JPY 32,800 to JPY 532,200). This converts to USD 707 at November 2013 rates. The authors report that this is comparable with the cost per quitter in companies with a smoke-free policy (USD 799), and lower than the cost of a smoker who quits without NRT through primary care or smoking specialist services (USD 2100 to 7900).

Milani 2009 presents the findings of their trial as an illustration to the employer of potential savings from an effective healthcare intervention in the workplace. They comment that in the US nearly 60% of after-tax profits are spent on corporate health benefits, with 80% of such expenses incurred by 10% to 20% of the workforce. Before the intervention, total medical claim costs averaged USD 2981 per participant, but in the 12 months after the intervention declined in the intervention group to an average of USD 1539 per participant (P = 0.002), compared with USD 2522 per participant in the control group (P = NS). The authors report that "For every dollar invested in worksite intervention, $6 was realized in health care savings".

Absenteeism

One study of a comprehensive lifestyle intervention (Nilsson 2001) reported on mean number of sick days over the last four months of the first year of the trial. Mean sick days taken by the intervention group fell from 6.0 to 2.9 (P = 0.03), while the mean sick days taken by the control group for that period rose from 4.5 to 7.4 (P = 0.04). However, smoking was only one of several behaviours targeted in this trial, and the contribution of reduced smoking prevalence to absentee rates could not be separately estimated.

Discussion

Workplace interventions are heterogeneous. Although the workplace may offer particular opportunities for recruitment to programmes, many of the interventions tested in workplace studies are not specific to this setting. This is particularly true of interventions aimed at helping individuals to stop smoking. The effects of smoke-free policies and restrictions within the workplace are covered in a companion review (Callinan 2010).

Summary of main results

This updated review (latest search July 2013) identified 57 randomized or quasi-randomized trials (61 comparisons), with later trials tending to be of higher quality for both conduct and reporting. We report the main findings in the 'Summary of findings for the main comparison'. Ten trials of group behavioural therapy (1793 participants), eight trials of individual counselling (3516 participants), five trials of pharmacological interventions (1092 participants) and six trials of multiple interventions targeting smoking cessation (5018 participants) all found clear evidence in support of such worksite-based programmes. Work-based incentives programmes (five trials, 1928 participants) also demonstrated benefits, but this analysis was dominated by one large trial with positive findings that were not sustained when it was removed from the calculation. Self-help interventions, social support programmes, relapse prevention programmes and environmental cues did not demonstrate significant benefits when offered in the workplace. Although we identified 13 studies of comprehensive intervention programmes for multiple risk factors including smoking, we were unable to extract sufficient data for meta-analysis. Although there is a strong theoretical rationale for approaches that integrate smoking cessation with comprehensive health promotion and protection programmes in the workplace, formal studies of such approaches have failed to show that they significantly decrease overall prevalence of smoking.

In addition to effectiveness, it is clearly important for employers to consider the economic aspects of introducing smoking programmes in their workplaces. These issues are infrequently addressed in the studies included in this review, and those studies which do discuss the economic implications are difficult to compare. The absolute figures quoted vary across time and across countries, and the methods of calculating costs differ from one study to the next. Some studies calculate a cost per quitter from among the smokers only, while others use the entire workforce as the denominator. These approaches also take no account of smokers who are not enrolled in the programme, but who are nonetheless reached and affected by the programme's publicity, or by friends and family who participate. Given that the quitters among them may have been influenced by the presence of the programme, they might reasonably be counted among the programme's successes. Furthermore, it is inappropriate to base the calculations simply on the programme costs, without reference to other direct costs such as occupied space that could have been used differently, donated or discounted time and resources, and avoidance of future healthcare expenditure on continuing smokers. Some studies risk an over-simplified approach to the analysis, calculating the costs per quitter in the intervention group without reference to the costs per quitter in the control or pre-policy group. The intervention costs should be reckoned as incremental to those incurred by the control group, which can be seen as demonstrating the background or placebo rate.

Overall completeness and applicability of evidence

In this third update of our review, we are confident that rigorous ad hoc and routine searching have ensured that we have identified the key research to inform the review question. Previous iterations have been dominated by US-based trials, through a combination of funding resources and the material interests of employers who usually cover health insurance costs for their staff. It is notable that for this update we have been able to include a few recent trials set in developing countries; this arena is likely to become increasingly important as the big tobacco companies shift their focus to these areas, while smoking rates in high-income countries stabilise or decline.

Agreements and disagreements with other studies or reviews

In drawing conclusions about the effectiveness of these interventions we have placed the findings of the workplace studies in the context of what is known from systematic reviews that include non-workplace studies. Although the results of some of the individual studies considered in this review have inconclusive findings, most are consistent with the findings from other systematic reviews. On this basis, we conclude that there is strong evidence for an effect of group therapy, of individual counselling, of pharmacological treatments, and of multiple interventions for smoking cessation. The Cochrane review of group behaviour therapy (Stead 2005) showed that such programmes increase the likelihood of quitting, approximately doubling the odds of quitting (odds ratio (OR) 2.20, 95% confidence interval (CI) 1.72 to 2.81 compared with other formats; 13 studies; risk ratio (RR) converted to OR). This compares with the OR in this review for the group behavioural studies of 1.71 (95% CI 1.05 to 2.80). Only one included study (DePaul 1994) is common to that review and the relevant comparison in this update, making the two bodies of evidence relatively independent of each other. The Cochrane review of individual counselling (Lancaster 2005a) identified 18 trials in workplaces and other settings, with only one study (Windsor 1988) in common with this review. The OR for successful smoking cessation in the individual counselling review was 1.53 (95% CI 1.31 to 1.80; RR converted to OR), compared with the individual counselling OR in this review of 1.96 (95% CI 1.51 to 2.54). Pharmacological interventions (predominantly NRT) were also successful when mediated through the workplace, which was compatible with results in other settings (OR 1.78; 95% CI 1.68 to 1.88; 119 trials, Stead 2012; RR converted to OR), compared with the pharmacological interventions OR in this review of 1.98 (95% CI 1.26 to 3.11); the same analysis restricted only to NRT trials delivered an OR of 1.81 (95% CI 1.07 to 3.08). Self-help interventions conducted in the workplace generally did not deliver enhanced rates of smoking cessation (OR 1.16; 95% CI 0.74 to 1.82), which again is consistent with the findings of the Cochrane self-help review (OR 1.08; 95% CI 0.98 to 1.19; 32 studies; Lancaster 2005b, RR converted to OR).

A particular attraction of the workplace is that it provides a route of access for communicating about smoking and offering help to stop. However, participation rates are often low. A number of studies considered methods for increasing participation. This review found limited evidence that participation in programmes can be increased by competitions and incentives organized by the employer (see also Cahill 2011). One limitation of the existing evidence is that most studies were conducted in stable workplace settings which are becoming less common, as workers are increasingly mobile (for example, in the construction and transport industries) or on short-term contracts (as in many modern service industries). The assumption that the workplace is a good place for recruitment is only valid for certain types of workplace.

Authors' conclusions

Implications for practice

1. We found strong evidence that some interventions directed towards individual smokers increase the likelihood of quitting smoking. These include both individual and group counselling, pharmacological treatment, and multiple interventions to increase smoking cessation. All these interventions show similar effects whether offered in the workplace or elsewhere. Self-help interventions, relapse prevention and social support are less effective. Although people taking up these interventions are more likely to stop, the absolute numbers who quit are low.

2. We failed to detect an effect of comprehensive programmes targeting multiple risk factors in reducing the prevalence of smoking; however, this conclusion is based upon a narrative rather than a meta-analytical synthesis.

3. There was limited evidence that smoking cessation can be increased by competitions and incentives organized by the employer, although one trial demonstrated a sustained effect of financial rewards for attending a smoking cessation course and for long-term quitting.

4. The potential advantage of the workplace is that more people can be reached and participation in cessation attempts is thereby increased. However, participation rates are usually low even within workplaces.

Implications for research

1. A particular finding of this review is the sparsity of data on economic aspects of workplace cessation programmes. Future studies should include measurement of direct and indirect costs, and if possible, economically relevant outcomes such as absenteeism and productivity.

2. Further research is needed to establish which components of the largest trial of incentives (Volpp 2009) contributed to its enhanced success rates.

3. Further research would be valuable in low-income and developing countries, where high rates of smoking still prevail and smoke-free legislation is not widely accepted or enforced.

Acknowledgements

Michael Moher was the contact author on the original review and 2005 update, and was a co-author on the 2008 update.
We would like to thank Angela Harden for advice in the planning stage of the review, Rafael Perera for statistical support, Lindsay Stead for search strategies and for editorial guidance, Andrew Briggs for advice on the economic aspects, and Stephen Sutton, peer reviewers from the Department of Health, and Malgorzata Bala for comments and suggestions.

We thank Glorian Sorensen for supplying additional data for the 2008 updated version of the review.

For the current update, we thank Gunnar Bergström, Dal Lae Chin, Marco Mario Farrario, Annice Kim, Lydia Makrides, Brian Martinson, Soeren Mattke, Gauravi Mishra, Richard Milani, Weeza Noor, Cassandra Okechukwu and Lisa Quintiliani for providing articles or additional information, or both. We also thank Eleonora Fulcini and Yaling Yang for translations of Italian and Chinese articles.

Data and analyses

Download statistical data

Comparison 1. Individual Treatments
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Group behavioural therapy (various endpoints)10 Odds Ratio (Fixed, 95% CI)Subtotals only
1.1 Cessation81309Odds Ratio (Fixed, 95% CI)1.71 [1.05, 2.80]
1.2 Relapse prevention2484Odds Ratio (Fixed, 95% CI)1.15 [0.80, 1.65]
2 Individual counselling (various endpoints)83516Odds Ratio (Fixed, 95% CI)1.96 [1.51, 2.54]
3 Any self-help intervention (various endpoints)61906Odds Ratio (Fixed, 95% CI)1.16 [0.74, 1.82]
4 Pharmacological treatments (various endpoints)51092Odds Ratio (Fixed, 95% CI)1.98 [1.26, 3.11]
5 Social support (various endpoints)253Odds Ratio (Fixed, 95% CI)0.69 [0.18, 2.62]
Analysis 1.1.

Comparison 1 Individual Treatments, Outcome 1 Group behavioural therapy (various endpoints).

Analysis 1.2.

Comparison 1 Individual Treatments, Outcome 2 Individual counselling (various endpoints).

Analysis 1.3.

Comparison 1 Individual Treatments, Outcome 3 Any self-help intervention (various endpoints).

Analysis 1.4.

Comparison 1 Individual Treatments, Outcome 4 Pharmacological treatments (various endpoints).

Analysis 1.5.

Comparison 1 Individual Treatments, Outcome 5 Social support (various endpoints).

Comparison 2. Worksite Treatments
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Environmental support (various endpoints)43851Odds Ratio (Fixed, 95% CI)1.00 [0.60, 1.65]
2 Incentives (various endpoints)51928Odds Ratio (Fixed, 95% CI)1.60 [1.12, 2.30]
3 Comprehensive interventions65018Odds Ratio (Fixed, 95% CI)1.55 [1.13, 2.13]
Analysis 2.1.

Comparison 2 Worksite Treatments, Outcome 1 Environmental support (various endpoints).

Analysis 2.2.

Comparison 2 Worksite Treatments, Outcome 2 Incentives (various endpoints).

Analysis 2.3.

Comparison 2 Worksite Treatments, Outcome 3 Comprehensive interventions.

Comparison 3. Results of included studies
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Results of included studies  Other dataNo numeric data

Analysis 3.1.

Comparison 3 Results of included studies, Outcome 1 Results of included studies.

Results of included studies
StudyBaseline/follow-upSmoking outcomeValidated ?
Bergstrom 2008About 881 smokers across 4 companies risk-assessed and given SC classes and NRT; about 98 controls assessed onlyNo MA data, but logistic regression results over 10 timepoints for 3½ years. Significant reductions in gradient relative to controls in Companies 1 (-0.6), 2 (-0.92) and 4 (-0.45), not in Company 3 (-0.09).No indication of validation (all long-term data collected by post or phone)
Cambien 1981304 intervention smokers recalled at 2 yrs, and 306 control smokers. 195 participants lost to follow up, proportion of smokers not reported21.4% of intervention smokers quit, vs 13.4% of control smokers. Point prevalence at 2 yrs, not a significant differenceValidation by blood CO levels
Campbell 2002538 women in 9 worksites (4 exp, 5 control) completed all surveys (282 I, 256 C) to 18m.No raw data given for smoking, but prevalence went down by around 3% in both groups. No significant differences, and no p values.Self-report on all outcomes, no biochemical validation
Dawley 19912 US oil refineries randomized to eenviornmental anti-smoking campaign + SC programme, versus SC programme alone.7/16 smokers in the comprehensive programme site had quit at 5m, versus 3/14 at the SC only site.Self report only, no biochemical validation
DePaul 1987425 smokers in 43 corporations, randomised to group support programmes or self-help alone programmes
Attrition rate was 8% in both groups
6% vs 2% continuously abstinent (NS), 19% in both groups were abstinent at 12 months point prevalence.
Companies were the unit of analysis, similar results found using individual as unit of analysis.
(See also Cochrane Review 'Self-help interventions for smoking cessation')
Partial validation by salivary cotinine, with family and colleague report
DePaul 1989419 smokers in 38 worksites, randomised to experimental programme (206) and comparison programme (213). The attrition rate was 17% for Group worksites and 29% for Non Group worksite participants, so correcting the data for attrition would increase the apparent efficacy of the Group condition.At the company level of analysis the 12 month point prevalence quit rates were Group 26% vs No Group 16% (p<0.06); continuous abstinence rates were 11% (Group) vs 3% (No Group) (p<0.05).
Reported rates were not based on Intention to Treat, but on participation in the programmes. Correcting for attrition would increase the efficacy of the Group programme.
At 24 months, 30% of the Group smokers were abstinent, comnpared with 19.5% of Non-Group smokers (no p value).
(See also Cochrane Review 'Self-help interventions for smoking cessation')
Partial validation by salivary cotinine, with family and colleague report
DePaul 1994844 smokers in 61 worksites, randomised to Self-help [SH] (289), Incentives [I] (281) or Group support [G] (283).
12 month attrition rates were 52.5% in SH, 47.2% in I, and 37.5% in G.
12 month quit rates for sustained abstinence were 5.1% (n=79) SH, 11% (n=91) I, 31.2% (n=109) G (p<0.01). An Intention to Treat analysis, taking account of attrition, would further favour the intervention groups.
(See also Cochrane Review 'Self-help interventions for smoking cessation')
Validation by salivary cotinine at 6 months, and CO<9ppm at 12 months
Emmons 19992055 workers (28% smokers) completed all surveys from 22 worksites, and constituted the cohort.At 3 yr final follow up, 8.0% of the intervention smokers had quit for 6m, and 8.1% of the control smokers. 25.6% and 21.8% respectively claimed 7-day PP. Differences were non-significantSelf-report, with no biochemical validation
Erfurt 1991Four sites were assessed at baseline; Site 1 had 1096 smokers (45%), Site 2 598 (44%), Site 3 844 (41%) and Site 4 834 (44%).
At 3 year follow-up Site 4 had been significantly restructured.
Participation was affected by the intervention: 5% in Site 1, 9% in Site 2, 53% in Site 3 and 58% in Site 4.
Possible bias due to different baseline characteristics of people rescreened in site 3 & 4 limit interpretation of follow-up smoking prevalences: 41.6%, 40.6%, 36.1%, 31.0%
All sites had significant relative reductions in smoking: 7.8% (p<0.01), 10.6% (p<0.01), 11.7% (p<0.001), 13.2% (p<0.001).
Of those smoking in 1985 who were re-screened in 1988, 17.1% at Site 1 had quit, 17.6% at Site 2, 20.3% at Site 3 and 18.9% at Site 4 (NS).
Self-report only, not biochemically validated
Frank 198648 smokers initially randomised to three groups, with varying levels of hypnosis, booster and self-management training. A 4th group (15 smokers) was later recruited, with Group 2 interventions applied more intensively.
Attrition rate of 6% across the initial 3 groups at end of treatment, 17% at 3 months and 25% at 6 month follow-up.
No difference between the groups for smoking cessation 6 months after treatment, regardless of the frequency, length between sessions, or addition of behavioural methods. Quit rate was 20% for all groups, based on Intention to Treat.
Intensive intervention produced initially higher quit rates (60% at end of treatment), but this reverted to 20% by 6 months
(See also Cochrane Review 'Hypnotherapy for smoking cessation')
Salivary cotinine measured at 3 months, but self-report only at 6 months
Glasgow 198436 employees, randomised to abrupt reduction (13), gradual reduction (12) and gradual reduction + feedback (11).
Attrition at 6 months was respectively 4, 0 and 1.
At 6 months up to one third in the gradual condition were abstinent compared to no subjects in the abrupt condition (NS).
Intention to Treat analysis showed that the gradual reduction programme was more successful than the abrupt reduction (p<0.05)
CO<10 ppm at 6 months, weighing of cigarette butts
Glasgow 198629 employees randomised to Basic Programme (13) or Basic Programme + Social Support (16).
Attrition 7% at end of treatment, and a further 7% at 6 months
Consistent with previous findings, supportive social interactions were not related to treatment outcome.3/13 in the Basic Programme had quit at 6 months, and 3/16 in the Basic + Social Support Group (NS).
(See also Cochrane review 'Enhancing partner support to improve smoking cessation').
Self report, weighing of cigarette butts, CO monitoring and salivary thiocyanate
Glasgow 199319 worksites, random allocation to Incentive programme (474 smokers) or No Incentive programme (623 smokers).
Attrition rates at 1 year were 19% (I) and 24% (no I), and at 2 years were 27% and 32% respectively
At 2 year follow-up 49/344 (14%) were abstinent in the Incentives group, and 49/426 (12%) in the No incentives group (NS). Intention to Treat analysis would give more conservative quit ratesCO monitoring and salivary cotinine
Glasgow 199526 worksites, randomised to early or delayed interventions. 1222 employees were followed up at all assessment points to 2 years. years.Comprehensive programme; a 26% rate of cessation was noted across both longitudinal cohort groups (NS), and a 30% rate across both cross-sectional groups (NS). No significant differences were seen between the 2 types of interventionSelf report, not biochemically validated
Gomel 1993a28 ambulance stations randomized to 4 levels of risk reduction intervention. 128 baseline smokers followed for 1 yrNo significant differences between HRA and RFE groups at any follow-up point, nor between BC and BCI groups. HRA and RFE groups (68 smokers) were pooled and compared with 60 smokers in pooled BC and BCI groups. Continuous abstinence rates at 6m were 1% for HRA+RFE and 10% for BC+BCI (Fisher's Exact Test P = 0.05); 12m rates were 0% and 7% (P = 0.05).Serum cotinine validation used.
Groeneveld 2011115 intervention smokers got MI + phone counselling, and 123 controls received 'usual care'.PPA at 6 and 12m. Study used as denominators only those with complete follow-up data, who had attended at least 5 sessions. On this basis, 6m quit rates were (I) 31.2%, (C) 13.4%, and 12m (I) 23.75, (C) 19.5. Our ITT analysis gives 6m: (I) 21.7%, (C) 8.9%: 12m: (I) 16.5%, (C) 13%.No biochemical validation
Gunes 2007200 smokers randomized to 7-step behavioural programme or no intervention, followed for 6mMain outcome was movement through stages of change. Smoking cessation at 6m was (I): 6/100, (C) 2/100.Probably no validation (not mentioned)
Hennrikus 200224 worksites, randomised to 6 programmes, 4 worksites in each programme. 2402 smokers were surveyed at baseline and at 12 and 24 months. 85.5% response rate at 12 months, and 81.7% at 24.407 (17%) smokers signed up to programmes. 15.4% at 12 months and 19.4% at 24 months reported themselves as non-smokers.
Recruitment was significantly higher in the incentive sites (22% vs 12% p=0.0054), but did not translate into higher cessation rates.
Quit rates were consistently higher among programme registrants than among non-registrants, but the differential was greater in the non-incentive sites (15%) than in the incentive ones (6.7%), consistent with incentives attracting smokers less motivated to quit.
Self-report, validated by family member or friend.
A sample of quitters were asked to supply saliva, and were paid $25 if they complied.
Winners of cessation prize draws had to supply a valid saliva sample.
Hishida 2010257 smokers genotyped, given self-help booklet; 276 controls assessment only.At 12m, 15/257 intervention smokers had quit, versus 22/276 control smokers. Intervention smokers at genetically higher risk of smoking-related cancers (5.6% and 7.1%) did not perform differently from the low-risk smokers (4.9%, P = 0.723). Possible confounding by legislation preventing passive smoking.Self report only, not verified.
Hymowitz 1991Six worksites randomised to Full Programme or Group-only interventions. Participation was 50% in the Full Programme sites, and 44% at Group-only (NS).
193/252 smokers who began the quit programme completed it.
Randomisation was by worksite, but analysis was by individual.
At 12 months, 23/131 (18%) in the Full Programme arm had quit, while 27/121 (22%) in the Group-only arm had quit (NS).Self-report and expired CO < 8 ppm.
Kadowaki 2000263 male employees randomised to intervention (132) or control (131).
No attrition, as inclusion was compulsory.
Quit rates 17/132 (Intervention), 4/131 (Control) at 5-month follow-up (p=0.003). Male smoking decreased from 62.9% to 56.7% (p=0.04).
Delayed intervention in the control group lead to 13% quit rate (16/123)
Expired CO<9 ppm at baseline, 5 months and 12 months, and a urine test at 12 months
Klesges 19878 Oregon worksites (127 participating smokers), randomized to group behavioural intervention, + either a 2x2 competition component or a 2x2 relapse prevention componentAt 6m, 15/127 had quit; Competition sites 12%, no-competition 11%.CO < 10 ppm and saliva thiocyanate
Kornitzer 198030 Belgian factories (16,230 men) randomized to intervention (risk assessment, physician and written advice) or control (assessment only). tested at 2 yrs.High risk intervention group (n = 1268) reduced prevalence by 18.7% (84.5% to 68.7%), and high risk control group (n = 202) reduced by 12.2% (80.8% to 70.9%). P < 0.05.
Random sample comparison: 5% of intervention group (n = 327) reduced by 12.5%, compared with 10% control sample (n = 800) reduced by 12.6% (ns).
Self report only, no biochemical validation.
Kornitzer 1995374 employees randomised to Group 1(149, active patch + active gum), Group 2(150, active patch + placebo gum) or Group 3 (75, placebo patch + placebo gum)At 12 months, abstinence in Group 1 was 18.1% (NS), in Group 2 12.7% (NS) and in Group 3 13.3% (NS). Time to relapse was significantly longer in Group 1 compared with the other 2 groups (p=0.04).Salivary cotinine at baseline, and expired CO<10 ppm at subsequent checks
Lang 200030 worksite physicians (1095 smokers) were randomised to Group A (504, simple advice) or Group B (591, advice + support and 'contract').2 physicians dropped out post randomisation.
3.4% of baseline non-smokers in each group were smokers at 1 year follow-up.
The sustained abstinence rate at 6 months or more (A: 4.6%; B: 6.1%) was non-significant using the physician as the unit as analysis.
At 12 months, Group A had a quit rate of 13.5%, and Group B a rate of 18.4% (p=0.03)
Self-report, with CO<7 ppm validation on a subset of 231 subjects whose physicians had access to a CO monitor.
Li 1984871 employee smokers, randomised to Group 1 (simple warning) or Group 2(brief physician advice), stratified by normal/abnormal lung function.
After fine tuning, at 3 months 215 workers received counselling, while 361 received simple warning and 3 were excluded.
Attrition was 30%.
Counselled workers had an 8.4% abstinence rate at 11 months, compared with 3.6% in the control group (p<0.05).
Feedback on abnormal lung function was not significantly related to increased rates of quitting
Expired CO<10 ppm at 11 months follow-up in all quitters, and in a random sample of 379 continuing smokers
Malott 198424 employees randomised to controlled smoking Group (1) or controlled smoking + partner support Group (2).
Attrition 4% at 6 months
Few differences were observed between controlled smoking and controlled smoking plus partner support conditions either during treatment or at the 6-month follow-up. 25% of Group 1, and 17% of Group 2 were abstinent at 6 months (NS).
(See Cochrane review 'Enhancing partner support to improve smoking cessation').
Self-monitoring, butt counts, expired CO levels
Mayer 2010275 abstainers randomized by company to proactive phone counselling (134) or to worksite-based group counselling (141) for relapse prevention.No significant differences at 9m: Phone counselling 57.5% and group counselling 61.7% remained abstinent (P = 0.552).4-wk CA assessed by CO < 10 ppm, and by urinary cotinine ≤ 317 ng/ml.
Milani 2009Two sites chosen; 33 intervention smokers received comprehensive CV risk programme, including referral to SC programme, and 31 controls.6/33 intervention smokers quit at 6m, versus 0/31 controls. Cost effectiveness analysis reported.Not stated, but probably unvalidated.
Mishra 2010Tobacco users in 4 call centres (63 control, 204 intervention) received increasing levels of support and bupropion; controls got self-help leaflets. 99% received long-term counselling.6m PA at 12m rates were 4/63 (controls), 17/87 BPO2 (HE sessions + focus groups), 8/43 BPO3 (as BPO2 + individual counselling), and 15/74 BPO4 (as BPO3 + bupropion offered); high turnover (52.4%) but only 1% lost to follow-up.CO monitor < 6ppm.
Nilsson 2001113 workers randomised to intervention (65) or control (63).
Attrition at 12 months was 32% for the intervention group, and 24% for the control group. At 18 months the respective attrition rates were 34% and 27%.
Baseline prevalence for both groups was 65%. At 12 months the intervention group point prevalence rate was 37%, and the control group 63%. At 18 months, the rates were 40% (of 43) and 59% (of 46) respectively. This difference influenced the decrease in mean risk score from 10.3 to 9.0 after 18 months in the intervention group (P = 0.042)Self-report, not biochemically validated
Noor 201177 male intervention smokers randomized to 24 wks of Viva QS tablets + brief counselling; 78 male control smokers randomized to placebo tablets. Attrtition was 1 intervention and 3 controls at start of study.At wk 24 all pts had face-to-face meeting at workplace for smoking status. Intervention 20-wk CA quit rate 19/75, controls 9/72. Similar AEs (sore throat: I 28.8%, C 36.6%; dry mouth: I 17.8%, C 16.9%).All pts cotinine- (< 50 ng/ml) and CO- (< 8 ppm) tested at 24 wks, whether claiming abstinence or not. 54 24-wk urine samples not analysed, so only CO reliable.
Okechukwu 2009251 intervention smokers (4 sites) and 239 control smokers (6 sites) had 4m programme of counselling, self help, NRT and environmental cues. Attrition at 6m post-programme was I 2%, C 1.7%.At 6m, 22/245 intervention and 17/235 controls had PA quit. 2/10 sites had delayed assessment (8m and 9m).Not verified (fear of 'drug-testing, + possibility of industrial toxin contamination).
Omenn 1988402 employee smokers randomised within their preference for group or self-help programmes, to 3 programmes, MCP (1), RPP (2) or MTP (3).
7% attrition rate at 12 months.
Self-reported quit rates similar across all three group preference conditions but more missing saliva samples in self-help so validated rates lower.
All self-help programmes similar.
Results: Group 1 8/51, Group 2 10/57, Group 3 4/51 (NS)
SH1 7/76, SH2 9/82, SH3 6/85 (NS)
Salivary cotinine at 12 months < 35 ng/ml
Prochaska 200848 smokers randomized to the HRI group, 40 to the MI group, and 48 to the TTM group. Attrition was 25.7% at 6m (distribution NK)PPA at 6m ("at criteria") was estimated at 8/48 for HRI alone, 14/40 for HRI + MMI, 10/48 for HRI + TTM; 6m denominators not reported (no reply from authors), so we have applied 6m quit rates to baseline smoking rates.Not stated, but probably no validation.
Rand 198947 employees randomised to contingent payment/frequent CO monitoring group (17), non-contingent payment/frequent CO monitoring (16), non-contingent payment/ infrequent monitoring (14).
4 participants failed to abstain for 5 days, and were excluded before randomisation.
At 6 months 11 more participants had dropped out. Analyses were Intention to Treat at randomisation.
Contingent payment combined with frequent CO monitoring delayed but did not ultimately prevent participant relapse to smoking by the end of the six month follow-up. Contingent payment group had CO value at or less than 11 ppm significantly longer than the other two groups (p=0.03). CO monitoring alone had no effect on abstinence.
At six months, only 2 subjects ( 1contingent, 1 non-contingent) had achieved sustained abstinence.
Expired CO monitoring <12 ppm
Razavi 1999344 post-cessation abstainers randomised to psychologist support (135), ex-smoker support (88), or no formal support (121),12 months abstinence rates were 59/135 (43.7%) in the PG group; 33/88 (37.5%) in the SG group; 43/121 (35.5%) in no support group (NS).Expired CO and urinary cotinine. Unvalidated self-report (higher) were also given.
Rodriguez 2003218 smokers randomized to counselling + NRT (115) or minimal sporadic advice (103) in 3 Bilabao (Spain) worksites12 months continuous abstinence rates were 23/114 (20.2%) for the intervention group, vs 9/103 (8.7%) in the control group (P = 0.025).
NNT was 9 people treated for 3mss to produce 1 quitter
Expired CO <+ 10 ppm
Schröter 200638 smokers assigned to standard behavioural (SB) programme, 41 to relapse prevention (RP) programme.
Assessed at 12m for continuous and PP abstinence
12m continuous abstinence rates were 8/38 (21.1%) for SB, and 5/41 (12.2%) for RP.Self-reported, no biochemical validation
Shi 19922887 workers (533 smokers) across 9 Californian sites, partially randomized to 4 intervention levels. No non-intervention control group 2 yr cross-sectional survey of 1998 workers (250 smokers); Prevalence declined by 34% from 18% to 12% in Level 1 (p < 0.1); by 18% from 17% to 14% in Level 2 (p < 0.1); by 35% from 24% to 15% in level 3 (p < 0.01); by 44% from 14% to 8% in Level 4 (p < 0.01) Self-reported PP at HRA, not biochemically validated 
Shimizu 199953 volunteer employee smokers, randomised to intervention and control groups.After the 5 months of intervention, smoking cessation rate in the intervention group (19.2%) tended to be higher than that in the control group (7.4%), (NS).
Control group was given same programme after the 5 months for the intervention group. At six months after both groups were treated, overall cessation rate was 24.5%, and at one year was 13.2%.
Expired CO monitoring
Sorensen 1993Eight worksites, randomised to intervention (1885 workers) or comparison (1479 workers).
At baseline, 9 months before intervention, 34% of respondents were current smokers (I:39%;C:31%)
Six-month data were on only 7 of the 8 sites, because of ownership changes at the 8th. Six-month survey was of all smokers then employed, = 66% of originally surveyed employees.
Analyses were by individual, while randomisation was by worksite.
Analysis of all smokers, not just participants.
At the 6-month follow-up, 12% of smokers in the intervention group reported quitting, compared with 8.8% in the control group (p<0.05), controlling for age, sex & occupation.
Self-report only.
Baseline and follow-up salivary cotinines obtained for 52% of baseline smokers. These data were not analysed.
Sorensen 1996108 matched worksites (>28,000 workers), randomised to intervention or control conditions, though Florida center sites did not target smoking, leaving smoking outcomes available in only 84 worksites.Worksite was the unit of allocation and analysis. Baseline smoking data were not reported in detail.
There was a difference of 1.53% (NS) in the 6-month quit rates between intervention and control sites, and a reduction in prevalence from 24.5% to 21.2% (I), and from 25.8% to 21.8% (C), a difference between the 2 groups of 0.66% (NS).
Self-reported, no biochemical validation
Sorensen 1998Cohort analysis (2658 employees) of a randomised controlled study of 12 matched pairs of worksites.
Worksite was unit of allocation, but analysis was by individual.
PP abstinence for the 6 months prior to 2-year follow-up was 15% for intervention group and 9% for control group (p=0.123)
Blue-collar cessation rates for the 2 groups were 18% (I) and 9% (C), while the white-collar workers achieved higher rates in the control than in the intervention group; office worker rates were 2.5% (I) vs 5.1% (C), and professipnal/managerial rates were 14.2% (I) vs 18.6% (C).
Self-reported, no biochemical validation
Sorensen 2002Cross-sectional analysis (9019 at baseline [80%] and 7327 [65%] ) at six months follow-up, plus cohort analysis of 5156 employees who responded to both surveys (embedded cohort of 436 smokers).
Worksite was unit of allocation, but analysis was by individual.
At six months, point prevalence in the HP/OHS sites fell from 20.4% to 16.3%, and in the HP sites from 18.6% to 17%.
In the embedded cohort (825 smokers) at 6m, the HP/OHS quit rate was 11.3%, compared with the HP rate of 7.5% (OR=1.57, p=0.17). Within the cohort, blue-collar quit rates more than doubled in the HP/OHS sites (11.8%) compared with the HP sites (5.9%, p=0.04)
Self-reported, no biochemical validation
Sorensen 2007Baseline participants 674 workers, (354 Int/ 320 Cont).
188 smokers (101 Int, 87 Cont) completed baseline and 6m surveys
7-day self-reported PPA at 6m: Int: 19/101 (19%), Cont: 7/87 (8%) (P=0.03).
ITT analysis Int: 19/125 , Cont: 7/106, P = 0.04.
Self-reported, no biochemical validation
Sutton 1987270/334 interested smokers invited to nicotine gum cessation programme; the uninvited 64 represented a control group. 172 (64%) of invitees attended the 1st consultation, 163 the 2nd.
One-year follow-up rate was 99% (9% by phone).
12% (20/172) of those who attended the intervention course were abstinent at 12 months, compared with 1% (1/98) of those who did not accept the invitation, and 2% (1/64) of the control group; p values not given.Expired CO<11 ppm
Sutton 1988aVideo programme (smoking, plus seat-belt advice) was offered to all employees. 77 employees were randomised to DFF video (33) or seatbelt (44=control) videos.Abstinence rates (DFF: 3%, SB [control] 0%) were not significantly different from each other at 12 months follow-up, There was no significant difference in validated abstinence between the video groups and the non-participant group.Expired CO<11 ppm.
Sutton 1988b150 employees (smokers only) participated. 46 watched the DFF video, 50 watched a confidence-boosting version of the DFF video, and 54 (control group) watched LTK video.Abstinence rates (DFF: 11%, DFF+C 8%, LTK [control] 9%) were higher than in the other 3 studies, but not significantly different from each other
at 12 months follow-up. But there was a significant difference in abstinence rates between participant groups and the non-participant group (4%, p<0.05).
Expired CO<11 ppm.
Sutton 1988c197 employees (smokers only) participated. 56 watched the DFF video, 67 watched a less gory version of the DFF video, and 74 (control group) watched the TW video.
Non-responder smokers at baseline had higher smoking prevalence (45%) than responders (29%), suggesting some response bias.
Abstinence rates (DFF: 4%, DFF-G 3%, TW [control] 4%) were not significantly different from each other.
at 12 months follow-up. There was no significant difference in abstinence rates between the video groups and the non-participant group.
Expired CO<11 ppm.
Sutton 1988d179 employees (smokers only) participated. 62 watched the DFF video, 59 watched SL video, and 58 (control group) watched TW video.
Non-responder smokers at baseline had higher smoking prevalence (34%) than responders (22%), suggesting some response bias.
Abstinence rates (DFF: 3%, SL 2%, Tw [control] 5%) were not significantly different from each other at 12 months follow-up. There was no significant difference in validated abstinence artes between the video groups and the non-participant group.Expired CO<11 ppm.
Sutton 1988eFourth study (D) of the video studies groups provided a nested RCT. 161 continuing smokers at 3-month follow-up were randomised to intervention (79) or control (82).
40.5% response rate, attending at least one consultation.
22% (7/32) of attenders in the intervention group were abstinent at 12 months, compared with 2% (1/47) of the non-attending invitees, and compared with 2% (2/82)of the control group (p<0.001).
16% of intervention group achieved 'complete' sustained abstinence at 12 months, vs 2% control group (p<0.01).
Expired CO<11 ppm.
Tanaka 2006Six intervention sites matched to 6 control sites; Of 1017 intervention smokers who completed baseline and 36m follow-up, 125 participated in cessation campaign, and 79 accepted counselling + NRT.6m sustained abstinence at 36m ITT analysis was 8.9% (123/1382) intervention vs 7.0% (121/1736) control (P = 0.0467). Quit rates in both groups rose steadily over 36m.No biochemical confirmation
Terazawa 2001228 smokers randomized to intervention (117) or control (111). 25 smokers in the intervention group made a supported quit attemptPP 11.1% (13/117) in the intervention group at 12m, compared with 1.8% (2/111) controls. Continuous abstinence 6.8% (8/117) intervention, compared with 0.9% (1/111) controls. Fisher's Exact test 2-tailed P = 0.04Probably validated by expired CO
Volpp 2009878 smokers randomized to intervention (436) or control (442); all got information about local SC programmes, and intervention also got stepped rewards for cessation efforts and goals. Attrition (losses + withdrawals) by 18m was 29% intervention and 24% controls.At 15m or 18m 41/436 intervention and 16/442 control had quit (PA).Confirmed by cotinine in saliva or urine.
Willemsen 1998Four intervention worksites matched to 4 control sites (minimal self-help), giving 498 smokers who completed baseline survey and enrolled in programmes.Overall sustained abstinence quit rates at 6 months were 8% (9% for heavy smokers) in the comprehensive group, and 7% (4% for heavy smokers) in the minimal group (no p values given)Self-report, plus baseline Fagerstrom score.
At 4-month follow-up, 'bogus pipeline' procedure was used, and at 14 months salivary cotinines were collected from 41/79 quitters
Windsor 1988387 smokers randomly assigned to four groups, in a 2x2 factorial pre-/post-test design.
37 were lost to follow-up, and were counted as continuing smokers
As monetary incentives made no difference, groups 1&3 were compared with 2&4. Sustained abstinence at 1 year was 5.8% (11/190) in the self-help only groups, and 14.4% (27/188) in the self-help + counselling groups (p<0.001).Baseline salivary cotinine, and follow-up salivas at 6 weeks, 6 months and 1 year.

Appendices

Appendix 1. Search Strategy for Register

Strategy for Tobacco Addiction Group Specialised Register
via Cochrane Register of Studies (CRS)
#1 workplace*:TI,AB,KY,XKY,MH,EMT
#2 worksite*:TI,AB,KY,XKY,MH,EMT
#3 work:KY,XKY,MH,EMT
#4 occupational health:KY,XKY,MH,EMT
#5 #1 OR #2 OR #3 OR #4

(KY, XKY, MH & EMT are keyword fields)

Appendix 2. Search strategies for electronic databases

Strategies used for update in 2013

Strategy for EMBASE

1. health behavior/
2. health promotion/
3. health education/
4. prevention/ or primary prevention/
5. mass screening/
6. 1 or 2 or 3 or 4 or 5
7. workplace/
8. (smok* or tobacco).mp.
9. 6 and 7 and 8
10. limit 9 to exclude medline journals
11. ("2008" or "2009" or "2010" or "2011" or "2012" or "2013").yr.
12. 10 and 11

Strategy for MEDLINE

1. exp Health Behavior/
2. exp Health Education/
3. Health Promotion/
4. Healthy People Programs/
5. exp Primary Prevention/
6. 1 or 2 or 3 or 4 or 5
7. Work/
8. Workplace/
9. Occupational Health/
10. 7 or 8 or 9
11. (smok* or tobacco).mp.
12. 6 and 10 and 11
13. ("2008" or "2009" or "2010" or "2011" or "2012" or "2013").yr.
14. 12 and 13

Strategy for PsycINFO

1. health behavior/
2. health promotion/
3. health education/
4. health care psychology/
5. prevention/ or preventive medicine/
6. health screening/
7. 1 or 2 or 3 or 4 or 5 or 6
8. occupational health/
9. workplace*.tw.
10. 8 or 9
11. (smok* or tobacco).mp.
12. ("2008" or "2009" or "2010" or "2011" or "2012" or "2013").yr.
13. 7 and 10 and 11 and 12

Appendix 3. Glossary of tobacco-related terms

TermDefinition
AbstinenceA period of being quit, i.e. stopping the use of cigarettes or other tobacco products, May be defined in various ways; see also:
point prevalence abstinence; prolonged abstinence; continuous/sustained abstinence
Biochemical verificationAlso called 'biochemical validation' or 'biochemical confirmation':
A procedure for checking a tobacco user's report that he or she has not smoked or used tobacco. It can be measured by testing levels of nicotine or cotinine or other chemicals in blood, urine, or saliva, or by measuring levels of carbon monoxide in exhaled breath or in blood.
BupropionA pharmaceutical drug originally developed as an antidepressant, but now also licensed for smoking cessation; trade names Zyban, Wellbutrin (when prescribed as an antidepressant)
Carbon monoxide (CO)A colourless, odourless highly poisonous gas found in tobacco smoke and in the lungs of people who have recently smoked, or (in smaller amounts) in people who have been exposed to tobacco smoke. May be used for biochemical verification of abstinence.
CessationAlso called 'quitting'
The goal of treatment to help people achieve abstinence from smoking or other tobacco use, also used to describe the process of changing the behaviour
Continuous abstinenceAlso called 'sustained abstinence'
A measure of cessation often used in clinical trials involving avoidance of all tobacco use since the quit day until the time the assessment is made. The definition occasionally allows for lapses. This is the most rigorous measure of abstinence
'Cold Turkey'Quitting abruptly, and/or quitting without behavioural or pharmaceutical support.
CravingA very intense urge or desire [to smoke].
See: Shiffman et al 'Recommendations for the assessment of tobacco craving and withdrawal in smoking cessation trials'
Nicotine & Tobacco Research 2004: 6(4): 599-614
DopamineA neurotransmitter in the brain which regulates mood, attention, pleasure, reward, motivation and movement
EfficacyAlso called 'treatment effect' or 'effect size':
The difference in outcome between the experimental and control groups
Harm reductionStrategies to reduce harm caused by continued tobacco/nicotine use, such as reducing the number of cigarettes smoked, or switching to different brands or products, e.g. potentially reduced exposure products (PREPs), smokeless tobacco.
Lapse/slipTerms sometimes used for a return to tobacco use after a period of abstinence. A lapse or slip might be defined as a puff or two on a cigarette. This may proceed to relapse, or abstinence may be regained. Some definitions of continuous, sustained or prolonged abstinence require complete abstinence, but some allow for a limited number or duration of slips. People who lapse are very likely to relapse, but some treatments may have their effect by helping people recover from a lapse.
nAChR[neural nicotinic acetylcholine receptors]: Areas in the brain which are thought to respond to nicotine, forming the basis of nicotine addiction by stimulating the overflow of dopamine
NicotineAn alkaloid derived from tobacco, responsible for the psychoactive and addictive effects of smoking.
Nicotine Replacement Therapy (NRT)A smoking cessation treatment in which nicotine from tobacco is replaced for a limited period by pharmaceutical nicotine. This reduces the craving and withdrawal experienced during the initial period of abstinence while users are learning to be tobacco-free The nicotine dose can be taken through the skin, using patches, by inhaling a spray, or by mouth using gum or lozenges.
OutcomeOften used to describe the result being measured in trials that is of relevance to the review. For example smoking cessation is the outcome used in reviews of ways to help smokers quit. The exact outcome in terms of the definition of abstinence and the length of time that has elapsed since the quit attempt was made may vary from trial to trial.
PharmacotherapyA treatment using pharmaceutical drugs, e.g. NRT, bupropion
Point prevalence abstinence (PPA)A measure of cessation based on behaviour at a particular point in time, or during a relatively brief specified period, e.g. 24 hours, 7 days. It may include a mixture of recent and long-term quitters. cf. prolonged abstinence, continuous abstinence
Prolonged abstinenceA measure of cessation which typically allows a 'grace period' following the quit date (usually of about two weeks), to allow for slips/lapses during the first few days when the effect of treatment may still be emerging.
See: Hughes et al 'Measures of abstinence in clinical trials: issues and recommendations'; Nicotine & Tobacco Research, 2003: 5 (1); 13-25
RelapseA return to regular smoking after a period of abstinence
Secondhand smokeAlso called passive smoking or environmental tobacco smoke [ETS]
A mixture of smoke exhaled by smokers and smoke released from smouldering cigarettes, cigars, pipes, bidis, etc. The smoke mixture contains gases and particulates, including nicotine, carcinogens and toxins.
Self-efficacyThe belief that one will be able to change one's behaviour, e.g. to quit smoking
SPC [Summary of Product Characteristics]Advice from the manufacturers of a drug, agreed with the relevant licensing authority, to enable health professionals to prescribe and use the treatment safely and effectively.
TaperingA gradual decrease in dose at the end of treatment, as an alternative to abruptly stopping treatment
TitrationA technique of dosing at low levels at the beginning of treatment, and gradually increasing to full dose over a few days, to allow the body to get used to the drug. It is designed to limit side effects.
WithdrawalA variety of behavioural, affective, cognitive and physiological symptoms, usually transient, which occur after use of an addictive drug is reduced or stopped.
See: Shiffman et al 'Recommendations for the assessment of tobacco craving and withdrawal in smoking cessation trials'
Nicotine & Tobacco Research 2004: 6(4): 599-614

What's new

DateEventDescription
25 October 2013New citation required but conclusions have not changed10 new trials added to Included studies, and 8 to Excluded studies, with 2 new ongoing and 1 awaiting classification. Four previously included trials now excluded. 'Risk of bias' tables and figure generated for all included studies. We include meta-analyses of the main categories, which quantify and consolidate our previous findings.
25 October 2013New search has been performedNew searches run and incorporated.

History

DateEventDescription
22 May 2008New search has been performedFour new included studies added (behavioural interventions). Review restructured to exclude bans and restrictions, which are now covered in a separate review.
Forest plots changed from OR to RR.
16 May 2008New citation required but conclusions have not changedOrder and names of authors amended.
23 April 2008AmendedConverted to new review format.
19 February 2005New citation required and conclusions have changedSubstantive amendment

Contributions of authors

KC and TL extracted and checked the data for the current update (2014).
KC produced full 'Risk of bias' tables for all included studies.
KC conducted meta-analyses.
KC wrote the update, with editorial input from TL.

Declarations of interest

None known

Sources of support

Internal sources

  • Department of Primary Health Care, Oxford University, UK.

  • National School for Health Research School for Primary Care Research, UK.

External sources

  • NHS Research & Development Programme, UK.

Differences between protocol and review

For the 2014 update, we have constructed meta-analyses for the main categories of intervention. We also now include 'Risk of bias' tables with a summary figure (Figure 1), and a 'Summary of findings for the main comparison'.

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Bergstrom 2008

Methods

Country: Sweden

Setting: 4 intervention sites (2 paper mills, 1 steelworks, 1 truck manufacturer), 1 'reference' [control] site (4 paper industry companies associated with one of the paper mills).

Design: Prospective multicentre cohort study, run from 2000 - 2003

Participants741 workers at the reference site, 387 at Company 1, 541 at Company 2, 1144 at Company 3, 2045 at Company 4. Baseline smoking prevalence at each was 13.3%, 16.2%, 27.1%, 20.5% and 21.3% respectively. Mean 12% women; mean age 41.3
Interventions

1. Intervention: Personal feedback provided after screening; smokers assessed at moderate or high risk got individual and group counselling, and NRT. High-risk smokers were offered full-time behavioural rehab programmes for 2 or 4 weeks. Some companies self-initiated self-help SC groups. The whole screening/feedback/intervention cycle was offered 3 times over the course of the study.

2. Control: In 2001 (yr 2), employees completed a questionnaire on the pyschosocial work environment, and received tailored feedback. No other interention.

Population measures taken 10 times over 4 years.

Outcomes

Lifestyle (smoking and exercise), health-related quality of life, sick leave.

Smoking prevalence at each time point, recorded by OHS, who also did spirometry and PEF, to year 4, probably based on self-reported PPA.

Type of intervention8. COMPREHENSIVE
NotesNew for 2014 update. This is the AHA study (Arbete och Hälsa inom process och verkstadsindustrin [Work and health in the processing and engineering industries]), funded by AFA Insurance.
Additional smoking data supplied by the author.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskNot randomized; reference sites had more white-collar workers (34%) than the interventions sites (26%, 25%, 16%, 14%)
Allocation concealment (selection bias)Unclear riskN/A
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
High riskTime between feedback and referral shorter at Companies 1 & 2 than at 3 & 4.
Selective reporting (reporting bias)Unclear riskCompany 4 had very low response rates throughout

Cambien 1981

MethodsCountry: France
Recruitment: Worksite volunteers in 160 sections of an administrative organization.
Design: Randomized controlled trial. Randomization method not described
Participants3336 men aged 25 - 35 at baseline. 424 classified as at high risk of coronary disease, 868 at low risk. 304 intervention / 306 control smokers.
Mean cpd 8.9 intervention, 10.0 control
Interventions1. High-risk intervention participants recalled at 6m, 12m, 24m, low-risk at 12m, 24m. All intervention participants measured blood sample, weight, BP, no. of cpd. Given tailored advice on diet, alcohol and smoking at each visit.
2. Controls received no counselling or measurement between baseline and follow-up
OutcomesAbstinence/reduction at 2 yrs.
At 2yrs 568 (86%) of intervention group returned, and 529 (84%) of control group.
Validation: Blood CO
Type of intervention2. Intensive behavioural: INDIVIDUAL COUNSELLING
NotesThis trial was added to the 2005 update.
95 intervention participants lost to follow up were heavier smokers (+ 4.4 cpd) vs 100 control participants lost to follow-up (+ 0.4 cpd).
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"Sections were randomly assigned"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low riskRates reported
Selective reporting (reporting bias)Low riskExpected outcomes reported

Campbell 2002

MethodsCountry: USA
Recruitment: 10 small manufacturing companies in NC.
Design: Cluster RCT, no details of randomization
Participants859 blue-collar women at baseline (73% of eligible). 538 completed programme to 18m. 53% aged 40 or younger, 58% African American. Mean BMI 29. 30% I group, 22% C group smoked.
Interventions1. Intervention: computer-tailored 'magazine' with dietary, exercise, smoking advice, at baseline and 6m, plus social support at work from trained helpers in participants' chosen activity. N.B. No lay helpers offered smoking support.
2. Delayed intervention (control): One computer-tailored 'magazine at 6m, no social support.
OutcomesAbstinence at 18m: self-reported, no biochemical validation.
Type of intervention8. COMPREHENSIVE
NotesThis trial was added to the 2005 update.
Natural (lay) helpers declined training in smoking cessation, so this arm of the intervention was not available to participants trying to quit.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"Four worksites were randomized to the intervention group and 5 to the delayed intervention group"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskOnly the 62.6% who completed all 3 surveys were analysed
Selective reporting (reporting bias)Unclear riskVery little information on smoking cessation

Dawley 1991

MethodsCountry: USA
Recruitment: worksite volunteers in 2 comparable oil refineries in Southern Louisiana
Design: cluster-RCT, no details of randomization method
Participants30 smokers (14 at intervention site and 16 at comparison site)
76% male
Av. age: 39, av. cpd 21
Participation rate: not reported
Interventions1. Intervention: comprehensive programme of smoking control, discouragement, cinnamon sticks as cigarette substitutes, and smoking cessation
2. Control: smoking cessation alone
OutcomesSelf-reported smoking cessation at 5m with urinary cotinine validation
Type of intervention6. ENVIRONMENTAL SUPPORT
NotesIntroduction includes lengthy discussion of economic and health costs of smoking
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"One refinery was randomly assigned"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNo losses reported
Selective reporting (reporting bias)Unclear riskNothing stated

DePaul 1987

MethodsCountry: USA
Recruitment: Employees at 43 worksites, recruited prior to a 3w television smoking cessation programme.
Design: Cluster-randomization by worksite, matched for size
Participants233 smokers in 21 group discussion worksites, 192 in 22 non-group work sites.
Groups led by trained employees
Participation rate: not reported
InterventionsAll participants were given self-help manuals by company co-ordinators and instructed to view the televized segments
1. Twice-weekly group meetings
2. Self help alone
OutcomesAbstinence at 12m (multiple PP)
Partial validation by salivary cotinine or family/colleague report
Type of intervention8. COMPREHENSIVE
Notes 
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"Forty-three cooperating worksites were randomly assigned ..."
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low risk Attrition rates @ 12m reported (7.7% G, 8.3% NG)
Selective reporting (reporting bias)Unclear riskPercentages only reported, not raw numbers

DePaul 1989

MethodsCountry: USA
Recruitment: Employees at 38 worksites, recruited prior to a 3w television smoking cessation programme.
Design: Cluster-randomization by worksite
Participants419 smokers who participated in the worksite programmes, 206 Group, 213 No-Group conditions.
Participation rate: not reported
Interventions1. 6 x twice-weekly group meetings to coincide with the 3w television series, then monthly meetings for a year. Abstinent smokers and 5 of their family and 5 co-workers entered for a lottery at the final group meeting and 12m follow-up.
2. Self-help manuals only
OutcomesAbstinence from end of programme to 24m
Validation by saliva cotinine and co-worker or relative confirmation.
Type of intervention8. COMPREHENSIVE
NotesThis study featured monthly booster sessions and monetary incentives for abstainers, as a development of the design of the first De Paul study
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"a randomly selected half" got the Group discussions. No further information
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low riskAt 12m, 5.3% G and 8.4% NG lost
Selective reporting (reporting bias)Low riskAll expected outcomes reported

DePaul 1994

MethodsCountry: USA
Setting: 61 worksites
Design: Cluster-randomization by worksite
Participants844 smokers recruited; 289 Self Help (SH), 281 Incentives (I), 283 Group (G).
Av. age 38, Av cpd 21
72% women in SH, 58% women in I, 59% women in G
Participation rate: 58% in SH, 59% in I, 55% in G
InterventionsWorksite interventions timed to coincide with a mass media intervention consisting of a week-long smoking cessation series on TV, and a complementary newspaper supplement.
SH: Self-help manual (ALA Freedom from Smoking in 20 days)
I: Self-help manual and incentive payment of USD 1 for each day abstinent up to USD175
G: 6 group meetings over 3w followed by 14 booster meetings over 6m. Incentive payments. Handouts from same S-H manual. Maintenance manual (ALA A Lifetime of Freedom from Smoking)
OutcomesSustained abstinence at 12m
Validation: CO < 9ppm. Saliva cotinine at 6m only
Type of intervention1. Intensive behavioural: GROUPS
NotesDiscussion section includes some cost-benefit analysis.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"matched according to size and type, and then randomly assigned..."
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low risk5 companies dropped out between pretest and 6m. ITT analysis used for individuals.
Selective reporting (reporting bias)Low riskAll expected outcomes reported

Emmons 1999

MethodsCountry: USA
Setting: 26 worksites in RI and SE Mass (Brown University-based).
Only 22 sites completed the trial.
Design: randomized matched pair, following a cohort over 3 yrs. Randomization process not described.
Participants22 worksites, and 2055 participants who completed all surveys. No demographic differences between intervention and control groups. Smoking prevalence 28% across both groups.
Interventions1. Intervention sites: As with Working Well Trial (Sorensen 1996), but including physical activity; a combination of individual and environmental programmes, including space, showers, equipment and discounted membership of fitness facilities.
2. Control sites: Minimal care: Could offer 2 S-H smoking cessation programmes and 1 each on nutrition and physical activity.
OutcomesSelf-reported abstinence at 3 yrs for 6m prior to assessment, and 7-day PP.
No biochemical validation used.
Secondary outcome: movement through stages of change.
Type of intervention8. COMPREHENSIVE
NotesThis trial was added to the 2005 update.
This is the Working Healthy Project, nested within the Working Well trial.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"random assignment of worksites within pairs"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNot stated
Selective reporting (reporting bias)Unclear riskNot stated

Erfurt 1991

MethodsCountry: USA
Setting: 4 General Motors worksites, Michigan
Design: Cluster-randomization by worksite
ParticipantsRandom sample of 400-500 employees screened at baseline and followed up 3 yrs later.
Predominantly male, white, blue collar.
41-45% smoked at baseline, but in the rescreened sample only 41% in site 3 and 36% in site 4 smoked at baseline
InterventionsSmoking, high blood pressure & obesity targetted.
1 worksite was allocated to each of 4 conditions:
1. Wellness screening; identify risks & referral
2. As 1. + media, programme sign-up campaigns and classes
3. As 1. + media, program sign-up campaigns, menu of interventions including guided self-help, group or individual counselling + follow up
4. As 3 + follow-up counselling + Plant Organization including peer support, aimed at reducing relapse.
All sites initiated no smoking areas during the period.
OutcomesSelf-reported smoking status
Type of intervention6. ENVIRONMENTAL SUPPORT
NotesQuit rates were calculated by combining 1985 smokers and ex-smokers (i.e. at risk of relapse) as the denominator. If the calculation is based only on current smokers at 1985 compared with 1988 quitters, the results do not reach statistical significance.
Reduced prevalence at all 4 sites coincided with the setting-up of restrictive policies in each site.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"The plants were randomly assigned"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskITT analysis (all employees screened, whether or not they participated in intervention).
Selective reporting (reporting bias)High riskSome confounding of denominators by inclusion of ex-smokers

Frank 1986

MethodsCountry: USA
Recruitment: University of Missouri employees
Evaluation: determine the effects of various amounts of hypnosis and hypnosis plus behavioural sessions
Design: RCT, no details of randomization method
Participants63 smokers
Women: 62%
Median education: 16 yrs
Median income: USD 27,000
Participation rate: not reported
InterventionsIn the initial study, 48 subjects of the total (N = 63) used, were assigned to one of three treatments:
1. 4 hypnotherapy (HYP) sessions + booster
2. 2 HYP sessions
3. 2 HYP + 2 behavioural sessions + booster.
A follow-up group was later recruited composed of 15 participants who received 4 HYP + booster with less time between sessions.
OutcomesSelf-reported cessation at 3m and 6m, with saliva thiocyanate confirmation at 3m only.
Type of intervention1. Intensive behavioural: GROUPS
Notes 
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"Subjects from the initial sample were blocked on high and low median in pack years ... and scores on the Creative Imagery Scale and were then randomly assigned"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskLosses of 17% at 3m and 25% at 6m (distribution not reported).
Selective reporting (reporting bias)Low riskAll expected outcomes covered

Glasgow 1984

MethodsCountry:USA
Recruitment: telephone company employees
Design: RCT, no details of randomization method
Participants36 employees and spouses
69% women. Av. age: 37
Smoked: average of 18 yrs and on average 30 cpd
Participation rate: not reported
InterventionsGroup therapy
3 groups: 1. abrupt reduction 2. gradual reduction 3. gradual reduction with feedback pre- and 2 post-tests; 7 weekly meetings with goals of 50% reduction per week in abrupt group; 25% per week in gradual group; 25% per week with graphs of daily nicotine intake for gradual/feedback group.
OutcomesSelf report of smoking status and consumption at 6m, with CO validation and cigarette butt weight.
Type of intervention1. Intensive behavioural: GROUPS
NotesAnalyses were conducted on non-abstinent participants at end of treatment, to assess reduction efficacy.
Outcomes included changes in nicotine content (brand smoked), amount of cigarette smoked, and number of cigarettes smoked.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"Subjects were randomly assigned..."
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low riskLosses at 6 months reported (4 abrupt; 0 gradual; 1 gradual + feedback)
Selective reporting (reporting bias)Low riskAll expected outcomes reported

Glasgow 1986

MethodsCountry:USA
Recruitment: VA hospital, savings and loan association, and a health insurance agency employee volunteers
Design: RCT, no details of randomization procedure
Participants29 adult cigarette smokers
69% women. Av. age 33.5
Average 25 cpd
Fagerstrom score 5.7, indicating moderate levels of tobacco dependence.
Participation rate: not reported
Interventions1. Basic program (BP): 6 weekly group meetings - focused on making reductions in the no. of cpd and reductions in nicotine content. Midway through the programme participants given the option of either complete cessation or reducing the percentage of each cigarette smoked.
2. BP + social support (SS): the same treatment as the BP group; in addition, each BP+SS participant selected a partner who provided support and encouragement during non-work hours.
OutcomesSelf reports, examination and weighing of saved cigarette. Butts and 2 biochemical measures of smoking exposure, CO and saliva thiocyanate.
Type of intervention5. SOCIAL SUPPORT
NotesOutcomes included changes in nicotine content (brand smoked), amount of cigarette smoked, and number of cigarettes smoked. The influence of social support, or lack of it, was also assessed.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear riskParticipants assigned, and then "Groups were then randomly assigned"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk7% losses reported
Selective reporting (reporting bias)Unclear riskNot stated

Glasgow 1993

MethodsCountry: USA
Recruitment: 19 worksites in Oregon.
Design: Cluster-randomized RCT
ParticipantsWorksites from 140 - 600 employees. Smoking prevalence of 21 - 22%; Av age 40 - 41. 63% women. 474 in Incentives (I) Group, 623 in No incentives (NI) Group
InterventionsCompany steering groups ran the programmes
1. I Group members were paid USD 10 for each verified abstinent month, up to 10m, + monthly and end-of-programme lotteries. There was also a buddy scheme, with cash prizes to helpers.
2. NI Group operated their normal company policy, which usually restricted but didn't ban smoking
OutcomesCessation rates at 12m and 2 yrs, verified by CO and salivary cotinine
Type of intervention7. INCENTIVES
NotesAnalysis was at both worksite and individual level.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"worksites were stratified on number of employees and estimated smoking prevalence... and then randomized"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskLosses to follow-up (22% at 1 yr and 30% at 2 yrs) not included in the analyses but 99% of current employees at 1 yr and 97% at 2 yrs contacted.
Selective reporting (reporting bias)Unclear riskAll expected outcomes reported

Glasgow 1995

MethodsCountry: USA
Setting: 26 worksites in Oregon
Design: Cluster-randomized trial
Participants26 heterogeneous worksites in Oregon with between 125 and 750 employees - an average of 247.
Participation rate: at baseline, early intervention rate was 38% and delayed intervention 58%.
At 2-yr follow-up, early intervention rate was 40% and delayed intervention was 57%
InterventionsTake Heart Project, focusing on diet and smoking
Early intervention (multifaceted programme consisting of employee steering committee and a menu approach to conducting key intervention activities tailored to each site) vs delayed but similar intervention
OutcomesSelf-reported smoking cessation
Type of intervention8. COMPREHENSIVE
NotesThis is the Take Heart worksite wellness program. Other outcomes included dietary intake and cholesterol levels
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"matched on (1) type of industry ..., (2) number of employees..., and (3) a composite variable... The resulting matched pairs were then randomly assigned"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNot collected
Selective reporting (reporting bias)Unclear risk% of smokers by cross-sectional surveys

Gomel 1993a

MethodsCountry: Australia
Setting: 28 Sydney ambulance stations
Design: Cluster-randomized RCT. method of randomization not described.
Participants431 participants (88%) in 28 stations. av age 32 yrs. 128 smokers, mean cpd 17.9.
Interventions1. Health Risk Assessment (HRA): (10 stations, 40 smokers): Measurement of BMI, % body fat, BP, cholesterol, smoking status, aerobic capacity. Feedback given, with high-risk people referred to family GP. This minimal 30-minute intervention was the control group.
2. Risk Factor Education (RFE): (8 stations, 28 smokers): Same measures as HRA, + advice through manual and videos in a 50-minute session.
3. Behavioural Counselling (BC): (6 stations, 30 smokers). Same as RFE group, + up to 6 counselling sessions (averaged 3) over 10w, + staged change manual.
4. Behavioural Counselling + Incentives (BCI): (4 stations, 30 smokers).
As RFE, + manual and goal-setting and follow-up counselling (average 2 hrs). Also lottery draw for AUD 40 voucher if interim targets achieved, and final prize of AUD1000 for highest achieving station at 6m.
OutcomesBaseline, 3, 6 and 12m assessments.
PP abstinence at 12m, validated by serum cotinine.
Type of intervention2. Intensive behavioural: INDIVIDUAL COUNSELLING / INCENTIVES
NotesThis trial was added to the 2005 update.
Fewer stations and participants were allocated to the more intensive interventions (BC and BCI) because of cost. Some contamination between conditions reported.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"Work sites were randomly allocated"; fewer stations (6/28 for BC, and 4/28 for BC+I) were allocated to the BC groups, to reduce costs.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low riskITT analyses performed. Losses reported for 3-, 6- and 12-month assessments.
Selective reporting (reporting bias)High riskOutcomes combined across groups; %s only. Staff moved between conditions throughout the study. "movement and transition of individuals between the different ambulance stations did occur", but no further details.

Groeneveld 2011

Methods

Country: Netherlands

Setting: All OHSs that perform Periodic Health Screenings (every 4 years to under-40s, every 2 years to over-40s) in the construction industry.

Design: RCT, conducted Jan 2007 - Feb 2008

Participants816 blue- and white-collar workers at > 400 companies at risk of CVD. 115 intervention and 123 control were the smoker cohorts. Mean age 47
Interventions

All OH physicians and nurses could apply to become lifestyle counsellors. All participants got brochures on physical activity, healthy eating, smoking and CVD.

1. Intervention 6-m counselling course, based on MI, 3 x 45 - 60-min face-to-face and 4 15 - 30-min phone sessions; Pts could focus on diet + (physical activity OR smoking).

2. Control: 'usual care', i.e. brief oral or written advice about their risk profile, based on screening results.

OutcomesQuestionnaires at 6 and 12m.
Type of intervention2. Intensive behavioural: INDIVIDUAL COUNSELLING
NotesNew for 2014 update. Study was funded by Stichting Arvouw
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"using Random Allocation Software (Version 1.0)", but prestratified by blue- or white-collar status.
Allocation concealment (selection bias)High riskProbably not (unblinded)
Blinding of outcome assessment (detection bias)
All outcomes
Low riskYes. "The investigator who performed the analysis was blinded to the group allocation".
Incomplete outcome data (attrition bias)
All outcomes
High riskAnalyses included only those with complete data (baseline, 6m, 12m) and had attended at least 5 sessions. Final denominator in analyses was 80/115 and 82/123.
Selective reporting (reporting bias)Unclear riskAll expected outcomes reported

Gunes 2007

MethodsCountry: Turkey
Setting: Textile factory in Malatya
Design: matched controlled study, followed up at 6m
Participants200 workers (425 smokers completed baseline questionnaire); 100 in each group, matched on age, education, working periods and amount smoked. Intervention and control groups worked different shifts. All male workforce, mean age 29.3, 81.7% married, 44.5% attended high school. Prevalence 65.9% smokers, 6.8% ex-smokers.
Interventions3-wk 7-step programme, based on stages of change model, and ALA programme.
OutcomesPrimary outcome was movement through stages of change, but 6m cessation rate also reported. PPA self-report, no verification.
Type of intervention1. Intensive behavioural: GROUPS
NotesReported as no attrition or losses to follow-up.
New for 2008 update.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot applicable.
Allocation concealment (selection bias)High riskNot randomised; 100 intervention versus 100 matched controls. Selection process not explained.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
High riskNothing reported; implication that there were no losses.
Selective reporting (reporting bias)High riskInsufficient information.

Hennrikus 2002

MethodsCountry: USA
Setting: 24 worksites in and around St Paul. No overlap with the Healthy Worker Project.
Design: Randomized 2 x 3 factorial design, with smokers followed up at 12m and 24m.
85.5% responded to 12m survey, and 81.7% to 24m survey.
Participants2402 smokers on 24 sites, 4 sites randomized to each of the 6 conditions. There were significant differences in demographic characteristics between sites.
Smoking prevalence ranged from 10.7% to 37.2%.
InterventionsThe 3 programme formats were group counselling, telephone counselling or a choice of group or phone.
The programmes were then offered with and without incentives (=6).
The incentive site smokers received USD10 for signing up to a programme, and USD 20 for near or full completion. They were also offered USD 20 for 30 days cessation, and were then entered into a prize draw for a USD 500 cash prize.
OutcomesRates of recruitment to the programmes, and 7-day smoking PP at 12m and 24m follow-up.
Validation was by self report, confirmed by family member or friend.
A sample of 188 quitters at 24m were asked to supply a saliva sample (128 complied).
Winners of the prize draw could only claim their prizes by verifying abstinence with salivary cotinine.
Type of intervention7. INCENTIVES
NotesThis is the SUCCESS Project.
Significant differences between worksites meant that several covariates had to be controlled for in the analyses.
Other outcomes included comparing quit rates of registrants for the programmes with non-registrants
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated.
Allocation concealment (selection bias)Unclear risk"Four worksites were randomly assigned to each of the six intervention conditions. Randomization was stratified by gender and education of the workforce".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Low riskLevel of non-responders reported.
Selective reporting (reporting bias)Low riskAll expected outcomes reported.

Hishida 2010

Methods

Country: Japan

Setting: Nagoya branch of Tokyo-Mitsubishi Bank

Design: Quasi-randomized controlled trial, conducted July 2002 - December 2002

ParticipantsSmokers identified at annual health check. 257/286 intervention smokers agreed to be genotyped and included; 100% of control smokers (276) agreed to participate. No sig baseline diffs, nor between the 257 genotyped and the 29 who refused.
Interventions

1. Intervention: Genotyped and classified for L-myc, modifying smoking-related disease risks. At 3m, genotype reports distributed, and any questions answered. No strong messages to quit.

2. Control: No intervention, follow-up at 12m.

All pts got a 8-page booklet on smoking and genetic polymorphisms; Stage of change established by baseline and 12m questionnaires.

OutcomesSmoking status and stage of change by group, and by L-myc genotype at 12m.
Type of intervention3. SELF-HELP
NotesNew for 2014 update. Trial funded by a grant-in-aid for Cancer Research from the Japanese Ministry of Health, Labour and Welfare.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot randomized; Alternate allocation by month to intervention (August, October, December) and control (July, September, November). No obviously raised risks.
Allocation concealment (selection bias)Unclear riskN/A
Blinding of outcome assessment (detection bias)
All outcomes
Low riskAssessor blinded. "Blood samples were numbered ... but the name of participants was not attached".
Incomplete outcome data (attrition bias)
All outcomes
Low riskLosses reported at 12m (Int: 16%, Cont: 11%). ITT analysis also included (with refusers).
Selective reporting (reporting bias)Unclear riskNone noted.

Hymowitz 1991

MethodsCountry: USA
Setting: 6 white-collar worksites. No worksite had a formal no-smoking policy or ongoing smoking cessation activities.
Design: Cluster-randomized trial
Participants6 worksites ranging in size from 950 to 3300 employees. 25% smoking prevalence.
252 employees aged 21 and older participated, representing only a small proportion of the total number of smokers at each worksite.
62% women. Av. age 42.3
> 60% White
Interventions1. Full programme (I): volunteers participated in a 5w training programme for quit-smoking group leaders, and received additional training, support, and how-to manuals to carry out a protocol for health education and sitewide intervention activities, as well as for the implementation of worksite smoking policies.
2. Group-only (C): volunteers participated in the training programme for group leaders, but did not carry out the protocols for health education and smoking policies.
OutcomesSelf-reported cessation at 12m
Validation: expired air CO
Type of intervention6. ENVIRONMENTAL SUPPORT
NotesUnit of randomization was worksite but unit of analysis was the individual.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"Six worksites were assigned randomly"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low riskDrop-outs fully reported
Selective reporting (reporting bias)Unclear riskAll expected outomes reported

Kadowaki 2000

MethodsCountry: Japan
Setting: single factory, 542 employees
Design: RCT, allocation by random number
Participants263 male smokers
Av. age 34, av cpd 19
Interventions1. Physician advice, CO feedback, cessation contract, self-help materials. follow-up over 5m. Smoking Cessation Marathon during month 4.
2. Delayed intervention control
OutcomesAbstinence for > 1m at 5m
(also 12m follow-up but by then control group also treated)
Validation: CO < 9ppm, plus urine test at 12m
Type of intervention2. Intensive behavioural: INDIVIDUAL COUNSELLING
NotesAll male smokers (62.9%) were entered compulsorily into the trial. Female smokers (3.4%) were not included.
Other outcomes included smoking reduction, willingness to quit and predictors of success.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"using a random number-generating software".
Allocation concealment (selection bias)Unclear riskNot stated.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk6% failed to complete final questionnaire.
Selective reporting (reporting bias)Low riskAll expected outcomes reported

Klesges 1987

MethodsCountry: USA
Recruitment: Employees from 4 worksites in Fargo, North Dakota and 4 in Eugene, Oregon
Design: Cluster-(worksite) randomization but individuals the unit of analysis. Two (competition/no-competition) by two (relapse prevention training/no relapse prevention training) factorial design
ParticipantsParticipants: 136 smokers from 8 worksites. Site size ranged from 50 - 380
Av. age: 38. av cpd: 28
Smoked: average 19 years
Participation rate: not reported - estimated 28% across all sites
InterventionsEvaluates the incremental effectiveness of competition and relapse prevention training in the context of a multicomponent cessation programme.
Multicomponent cognitive behavioural programme for 6 weekly sessions; within-site competition with weekly feedback on a visible barometer and monetary prizes at programme completion and at 6m; relapse prevention booster sessions were held at 1m and 2m intervals following the programme.
OutcomesCessation at 6m.
Validation: CO and saliva thiocyanate.
Type of intervention1. Intensive behavioural: GROUPS
NotesThe competition incentive was conducted within each intervention worksite, rather than between the worksites.
Other outcomes included relapse prevention, smoking reduction, nicotine levels (brands), % of cigarette smoked.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"The four worksites in each community were randomly assigned..." [2 competition/no competition, 2 relapse prevention/no replapse prevention at each of 2 sites].
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk7% attrition by end of treatment, and 10% by 6m.
Selective reporting (reporting bias)Unclear riskAll expected outcomes reported.

Kornitzer 1980

MethodsCountry: Belgium
Setting: 30 factories
Design: Cluster-randomized matched pair design RCT. Randomization method not described.
ParticipantsParticipants: 16,230 men aged 40 - 59 (83.7% of eligible men).
Interventions1. Intervention: All screened for height, weight, cholesterol, smoking, BP, ECG, personality and psychological testing. Top 20% at risk counted as the 'high risk' group, who received 6-monthly individual physician counselling. Complete cessation was encouraged, but pipes or cigars allowed if necessary. Advice booklet also supplied. All smokers of 5 or more cpd received written advice to quit. Environmental components included anti-smoking posters and a factory conference on dangers of tobacco.
2. Control: a 10% sample screened at baseline were followed up; the 20% of this sample with the highest risk score were also identified as the control 'high risk' subset, to be analyzed separately. The 'Design and Methodology' paper reports that all eligible men in the control factories all received an ECG, but this is not mentioned in later reports.
Outcomes7-day PP at 2 yrs follow up.
5% sample of intervention group (327 men) were tested, + all of the original high-risk group (1268). The 10% random sample control subjects were reviewed after 2 yrs, including the 20% high risk subgroup (202 men). Self report only, without biochemical verification.
Abstinence was defined as someone smoking at baseline who had been abstinent for at least the week before the 2-year assessment.
Type of intervention8. COMPREHENSIVE
NotesThis trial was added to the 2005 update.
This is the Belgian Heart Disease Prevention Project
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear riskFactories matched for size and industry, and "within each pair one is randomly allocated to intervention".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
High riskResults based on all high-risk smokers + 5% of total sample, versus 10% of control group. At 2yrs 28.5% of high-risk group lost; at 10 years 0.66% lost overall.
Selective reporting (reporting bias)Unclear riskNot stated; pipes and cigars allowed "if a substitute was needed".

Kornitzer 1995

MethodsCountry: Belgium
Recruitment: Worksite
Design: RCT, computer-generated list.
Participants374 volunteers
men and women, age > 20 yrs. No. of cigarettes: > 10 day for > 3 years.
Interventions1.Active patch and active gum (2mg as required).
2.Active patch and placebo gum.
3.Placebo patch and placebo gum.
High level of adjunct support.
OutcomesSustained abstinence at 12m.
Validation: baseline salivary cotinine, and expired CO < 10 ppm at each follow-up.
Type of intervention4. PHARMACOLOGICAL
NotesOther outcomes included dermatological and systemic adverse effects, and time to relapse.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"a randomized list generated by a computer program".
Allocation concealment (selection bias)Low risk"Subjects were allocated a number and a treatment plan".
Blinding of outcome assessment (detection bias)
All outcomes
Low riskParticipants and investigators blinded, packaging blinded.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskITT analysis; losses not reported.
Selective reporting (reporting bias)Low riskAll expected outcomes.

Lang 2000

MethodsCountry: France
Setting: Annual health check in one large gas and electric company
Design: Cluster-randomization by site physician, physician as unit of analysis
Participants28 site physicians covering 1269 smokers and 2614 nonsmokers
Av. age: 38, 82% male
Av cpd: 14
Interventions1. A: Low intensity [control] intervention: Physician advice 5 - 10 mins incl. leaflets
2. B: High intensity [intervention]: as 1. plus quit date, moral contract, follow-up phone call, and 2nd visit
OutcomesAbstinence (self-reported) for at least 6m at 1-yr follow-up
Validation: CO measurement in subgroup
Type of intervention2. Intensive behavioural: INDIVIDUAL COUNSELLING
NotesOther outcomes included BMI and depression score.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated; the scientific committee selected one unit from the list supplied by each physician.
Allocation concealment (selection bias)Unclear risk"one unit per physician was randomly selected".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Low riskITT analysis. Full report of those lost to follow-up, with reasons.
Selective reporting (reporting bias)Low riskAll expected outcomes reported.

Li 1984

MethodsCountry: USA
Setting: naval shipyard.
Recruitment: Smokers identified at worksite screening (unselected).
Design: RCT, no details of method
Participants871 male asbestos-exposed smokers
Av cpd: 24 - 26
Interventions1.Advice from occupational physician; minimal warning, results of pulmonary function tests, leaflets
2. As group 1 plus behavioural counselling
OutcomesSustained abstinence at 11m.
Validation: expired CO.
Type of intervention2. Intensive behavioural: INDIVIDUAL COUNSELLING
Notes

Other outcomes included stratification by lung function, reduction by continuing smokers, predictors of successful quitting and characteristics of smokers refusing to participate in the study.
Randomization ratio (method not explained) changed halfway through the study from 3:1 to 1:1.

The study found wide variation in implementation of the study procedure by physicians.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)High riskAllocation ratio changed at 3m from 3:1 to 1:1; also only 215/359 experimental group received the counselling, while 361/220 got minimal advice [3 deleted because advising physician NK]. Groups had to be "reconstituted".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
High risk24% lost at 3m (assessments changed from at-work to at-home); 14% lost at 11m follow-up.
Selective reporting (reporting bias)Unclear riskExpected outcomes reported.

Malott 1984

MethodsCountry: USA
Setting: volunteers from telephone company (8) and a medical clinic (16)
Design: RCT, no details of randomization method
Participants24 participants av age 34, had smoked for an average of 16 years, and av cpd 24.
Average score on the Fagerstrom NTQ 6.0
Participation rate: not reported
InterventionsGroup therapy
1. controlled smoking
2. controlled smoking plus partner support
OutcomesSelf-monitoring records, laboratory analyses of spent cigarette butts, and CO at 6m
Type of intervention5. SOCIAL SUPPORT
NotesOther outcomes included nicotine levels (brand smoked), smoking reduction, CO levels in continuing smokers and % of cigarette smoked.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated.
Allocation concealment (selection bias)Unclear risk"groups were then randomly assigned".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Low riskOne lost to follow-up (moved away).
Selective reporting (reporting bias)Low riskAll expected outcmes reported.

Mayer 2010

Methods

Country: Belgium

Recruitment: Successful abstainers from a smoking cessation programme.
Design: Cluster-RCT in 42 companies (industry not specified). Conducted from December 1993 - June 1997.

Participants275 self-reported abstainers, mean age 40, 75% male, allocated to proactive phone counselling (141) or to worksite-based group counselling (134) for relapse prevention. Each pt paid EUR 50 to participate (14.5% were paid for by their employers).
Interventions

1. PPC [proactive phone counselling]: 10 sessions, 2 in first month and then monthly; 5 calls over 7 days to recruit; sessions lasted a minimum of 10 minutes.

2. WGC [workplace group counselling]: 10 sessions, in a work-based room, either during or after worktime; each session lasted 90 minutes, with 5 - 10 participants.

All sessions addressed potential lapses, high-risk situations, strategies and compensatory behaviours.

Outcomes4-week CA at session 11 (12m after quit date), checked by CO < 10 ppm and urinary cotinine < 317 ng/ml.
Type of intervention1. Intensive behavioural: GROUPS
Notes 
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

"Workplace randomization was based on using a single sequence of random assignments produced by a computer program".

Comment: Not clear exactly what was done, or why it could not be subverted.

Allocation concealment (selection bias)Unclear riskNot stated.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Low riskDrop-outs reported, with reasons.
Selective reporting (reporting bias)Unclear riskExpected outcomes reported.

Milani 2009

Methods

Country: USA

Setting: 2 worksites (1 company); type of industry not reported.

Design: Cluster-randomized trial

ParticipantsEmployees + spouses with health insurance through a single employer-sponsored provider. 185 intervention site (33 smokers), 154 control site (31 smokers).
Interventions

1. Intervention: 6m programme of CV-risk reduction counselling (nutrition, smoking, physical activity). Smoking covered by "referrals to group smoking cessation programs".

2. Control: "usual care"

OutcomesSmoking prevalence at 6m; costs at 12m.
Type of intervention8. COMPREHENSIVE
NotesNew for 2014 update. Author provided additional information.
Funding sorce not stated, but trialists run a company (Oschner Health System) that sells these services to local workforces.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot reported.
Allocation concealment (selection bias)Unclear riskNot reported.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Low risk3 dropped out of intervention group, none from control group.
Selective reporting (reporting bias)High riskSmoking results acquired from author, not from study report.
Some contamination possible between sites (may not have affected smoking subgroups).

Mishra 2010

Methods

Country: India

Setting: 4 Business Process Outsourcing (call centre) sites in Mumbai

Design: 4-arm cluster-randomized trial, each arm around 200 employees; 12-m programme spread over 18 months study duration.

ParticipantsAll 992 employees invited, and 646 participated. 267 (41.3%) were tobacco users (the denominator for the trial). BPO 1 (control) had highest prevalence (56.7%), BPO3 the lowest (22.2%). N of tobacco users was BPO1: 63; BPO2: 87; BPO3: 43; BPO4: 74. BPO3 was admin-based, while the others were public-contact call centres.
Interventions

BPO1 (control): Pamphlets to all employees on hazards of tobacco, how to quit.

BPO2: Active health education sessions (slide show, for anyone) + focus groups of 7 - 10 smoking employees; these became support groups for quitters and quit-attempters.

BPO3: As BPO2, + individual counselling.

BPO4: As BPO3, + optional bupropion based on individual needs assessment (offered to 24 but only 10 used it).
Regular follow-up every 2 - 3 months, final assessment at 12m.

OutcomesSustained cessation for 6m, verified by "smoke-check" CO monitor, expired CO < 6 ppm; reduction. Comparison used was 1 (controls) versus 2 (groups).
Type of intervention1. Intensive behavioural: GROUPS
NotesNew for 2014 update.
Funding was by Intramural grants from the Tata Memorial Hospital.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk"Each of the 4 BPO units was randomly assigned using lottery methods".
Allocation concealment (selection bias)Unclear riskNot stated.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Low risk52.4% of tobacco users by 12m had changed jobs; follow-up and counselling conducted by phone for those who had left. 1% not traced.
Selective reporting (reporting bias)Unclear riskNone noted.

Nilsson 2001

MethodsCountry: Sweden
Recruitment: 4 public sector worksites (568 employees) in Helsinborg.
Design: RCT
Randomization: method of allocation not stated.
ParticipantsOf 128 at-risk workers invited, 60/65 randomized to the intervention group attended for baseline assessment, and 53/63 from the control group.
Mean age was 49.7, 61% women.
Interventions1. Intervention group received 16 group sessions a year, as well as individual counselling by a nurse. Sessions included lectures, discussions, video sessions and outdoor activities.
2. Control group received standard written and oral advice about cardiovascular risk factors at the start of the intervention, and nothing thereafter.
OutcomesPP at 12m and 18m. No biochemical validation.
Type of intervention8. COMPREHENSIVE
NotesSmoking was only one of several risk factors targeted, including BMI, BP, heart rate, low-density lipoprotein and cholesterol.
Group sessions were held in working hours but away from the worksites.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated.
Allocation concealment (selection bias)Unclear risk"The persons ... were randomized".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Low riskDrop-outs fully reported.
Selective reporting (reporting bias)Unclear riskAll expected outcomes reported.

Noor 2011

Methods

Country: Kerteh and Kuantan, Malaysia

Setting: 11 industrial workplaces (type not stated) in two towns (not cluster-randomized)

Design: RCT, conducted from April to October 2008

ParticipantsMale smokers (FTND > 4) invited from those attending mobile SC clinic; 48% between 31 and 45 yrs of age, baseline FTND mean 50% 7 - 10.
Interventions

1. Viva QS: (77) a "herbal medication" "twelve herbs mainly found in Korea and China".

2. Control: (78) placebo tablets.

All pts asked to set TQD (day 8), and given 24-wk supply of tablets. All pts phoned at wks 2 and 4, given 5 - 10 mins counselling. At wk 12 all had face-to-face session of brief counselling and smoking status checked with CO testing; those not available were phoned.

Final assessment at wk 24, with bio-confirmation (CO < 8 ppm, cotinine). Any lost or unconfirmed counted as smokers.

Outcomes7-day PPA, CA wks 4 - 12. CO validated at wks 12 and 24. Cotinine validation (50 ng/ml) for all pts, whether self-reporting abstinence or not. Adverse events.
Type of intervention4. PHARMACOLOGICAL
Notes

New for 2014 update; publication supplied by the author.

Funding was by Viva and Revival Productions Sdn Bhd

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"The manufacturer was responsible for the randomization".
Allocation concealment (selection bias)Low risk"the medication packs were numbered from 1 to 155"; "Subjects were assigned to a specific treatment number based on the provided randomization code".
Blinding of outcome assessment (detection bias)
All outcomes
Low risk"There was no difference between placebo and Viva QS in appearance, color, and shape of the capsules, and were packaged in identical blister packages and boxes. Viva QS used was from the same production batch. The administration of the capsules was conducted on a double-blind basis i.e. all subjects and researchers had no information on who received Viva QS or placebo".
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk1 intervention and 3 placebo pts excluded because lost to follow-up at baseline; but denominators used were -2 int and -6 controls. 29 validated results as wk 12, versus 111 self-reported.
Selective reporting (reporting bias)High riskValidated outcomes reported for 7-day PPA, but not for CA. 54 urine samples collected but not analysed (lab problem).

Okechukwu 2009

Methods

Country: USA (Massachussets)

Setting: 10 unionised building sites (4 intervention, 6 control)

Design: RCT (cluster-randomised), conducted 2004 - 2007.

Participants624 (251 smokers) intervention trainees, 560 (239 smokers) control trainees completed all three surveys = working cohort. Mean age 28, 95% male, smoking prevalence 41%.
Interventions

4-month programme, conducted in work time.

1. Intervention:

(a) Toxics and tobacco curriculum; 2 x 1-hour modules on work-related hazards added to smoking risks.

(b) Group-based SC counselling: 8-week course on MI principles at each site; 3 - 12 people per group.

(c) Free NRT patches to any intervention smoker, regardless of other interactions.

(d) DIY quit kits; self-help materials, including SC guide.

(e) Environmental cues: posters, support materials.

Those who attended got early release from classes, and meals. Those who completed 7/8 sessions entered into cash raffle. Survey completers got a USD 10 store voucher.

2. Control:

Assessment only, at 3 time points, but received full programme after study end.

OutcomesSmoking status (PA) at 1m, 6m. 7-day PPA at 1m. Not biochemically verified (to avoid 'drug-testing' association). Also smoking reduction, number of quit attempts. Time 3 (6m) slipped to 8m for 1 site and 9m for another.
Type of intervention8. COMPREHENSIVE
Notes

New for 2014 update; additional information supplied by the author.
This is the MassBuilt study.

Funded by grant 1R01 DP000097-01, National Institutes of Occupational Safety and Health;

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"The statistician (YL) for the study separated the group into two groups of large and small sites then he used random number generator to manually randomize the sites into intervention and control groups" (personal communication from the author).
Allocation concealment (selection bias)Unclear riskNot stated.
Blinding of outcome assessment (detection bias)
All outcomes
Low risk"We used different sets of research personnel for th intervention and data collection" (personal communication from the author).
Incomplete outcome data (attrition bias)
All outcomes
Low riskOnly those that completed all 3 surveys were used. But ITT and cross-sectional sensitivity analyses showed no differences in findings.
Selective reporting (reporting bias)Unclear risk

Site was unit of randomization, while individual was unit of analysis.

Might have been contamination between intervention and control on building sites.

Omenn 1988

MethodsCountry: USA
Recruitment: Single worksite (13,000 workers, 9 employers)
Randomization: by nurses at aid stations using randomized assignment lists generated by research centre, within preference for format.
Participants159 smokers (av. age 43, 66% male, av.cpd 25) with preference for group programme or no preference.
243 smokers with a preference for self help randomized to 3 different S-H programmes
Groups lead by instructors trained in both programmes.
Participation rate: 11%
InterventionsGroup therapy preference:
1. Multiple Component programme. 3 sessions over 3w
2. Relapse Prevention programme. 6 sessions over 6w
3. Minimal Treatment programme. Self-help materials only. American Cancer Society's 22 page 'Quitter's Guide' 7-day plan.
S-H preference:
Same 3 programmes, all in manual form, with no group meetings.
OutcomesAbstinence at 12m (single PP)
Validation: saliva cotinine <= 35ng/ml
Type of intervention1. Intensive behavioural: GROUPS / SELF HELP
NotesGroup programmes were held away from worksite in non-work hours.
50% random sample of continuing smokers supplied salivary samples
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"randomized assignments that had previously been generated at the research center"
Allocation concealment (selection bias)Low riskSmokers could choose self-help or group format and were then randomized within that. Randomization was by nurses trained in this procedure. "Our system ... indicated that the nurses successfully followed the protocol".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskFailed to complete course: MCP 24%, RRP 58%, MTP-group 69%, MTP-self 60%. ITT analyses conducted.
Selective reporting (reporting bias)Low riskAll expected outcomes reported.

Prochaska 2008

Methods

Country: Oregon, USA

Setting: Medical University
Study design: RCT

Participants1400 employees, randomized to health risk assessment intervention (HRI: 464; 48 smokers), HRI + MI counselling (433; 40 smokers) or HRI + interactive TTM programme (TTM: 503; 48 smokers). Study targeted 4 risk-reduction programmes: stress, exercise, weight control and smoking. 11% M, mean age 41, mean CPD N/S.
Interventions

Intervention 1: MI: HRA + 3 x phone or face-to-face MI sessions, to move along SoC and reduce risky behaviour.
Intervention 2: TTM: HRA + online TTM programme (Pro-Change Lifestyle Management Program); 4 programmes over 6m; recommended 3 sessions of each course.

Control: Health risk assessment (HRA) only. SoC assessed for each risk, and identified single best step to remedy.

Outcomes'Reaching criterion' at 6m, i.e. PPA (no longer at risk) for smokers.
Validation: None.
Type of intervention8. COMPREHENSIVE
Notes

New for 2014 update; No 6m denominators reported, but 101/136 smokers reported to have completed (Table 3). No reply from authors.

Funded by CDC grant 1 RO1 DP000103.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk"randomly assigned".
Allocation concealment (selection bias)Unclear riskNot stated.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk35 smokers lost by 6m; distribution not reported. We conducted ITT analysis.
Selective reporting (reporting bias)Unclear riskNot stated.

Rand 1989

MethodsCountry: USA
Recruitment: Smoking volunteers employed at Francis Scott Key Medical Center, Baltimore.
Design: RCT, no randomization detail
Participants47 subjects who completed 5 days verified abstinence.
Interventions1.Contingent payment for continued abstinence + frequent monitoring (n = 17)
2. Non-contingent payment for abstinence + frequent monitoring (n = 16)
3. Non-contingent payment, infrequent monitoring (n = 14).
OutcomesQuit rate at 6m, confirmed by CO validation.
Type of intervention7. INCENTIVES
NotesSubjects had received a minimal cessation programme, i.e. a 15-minute talk and a booklet, with no skills training in cessation or relapse prevention.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated.
Allocation concealment (selection bias)Unclear risk"randomly assigned".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Low riskLosses reported.
Selective reporting (reporting bias)Unclear riskAll expected outcomes reported.

Razavi 1999

MethodsCountry: Belgium
Recruitment: workplace volunteers in 32 companies.
Design: Open-label cessation phase, then RCT for relapse prevention, using random numbers and blinded list
Participants344 quitters, abstinent for at least 1m at end of 3m X 7 cessation programme including group therapy and NRT.
38% women, av age 39.
Interventions1. Relapse Prevention (RP). 10 sessions inc group discussion and role play led by professional counsellor.
2. RP. 10 sessions of group discussion led by former smokers.
3. No RP
OutcomesAbstinence for 9m from start of RP programme.
Validation by expired CO < 10 ppm and urinary cotinine ≤ 317 ug/ml.(Rates for CO and self report alone also reported; higher than for doubly validated rates)
Type of intervention1. Intensive behavioural: GROUPS
NotesAll participants for this study had achieved abstinence after a 3m group and NRT programme. This is a relapse prevention study, rather than cessation.
Other outcomes include predictors of sustained abstinence, weight gain.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskRandomization by company; "a printed randomisation list".
Allocation concealment (selection bias)Low riskRP phase: "Randomisation was performed by using a provided list of random number (hidden by a label) to assign the follow-up regime."
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskITT analysis; drop-outs not reported.
Selective reporting (reporting bias)Low riskAll expected outcomes reported.

Rodriguez 2003

MethodsCountry: Spain
Setting: 1 transport company (mostly bus drivers) and 2 electrical utility worksites (mostly clerical) in Bilbao.
Design: Open RCT, with randomization by sealed opaque envelopes and computer-generated random lists
Participants218 participants randomized to intervention (115) and control (103). All had physical check up, Fagerstrom NTQ, lab tests and ECG at baseline
Interventions1. Intervention: 5 - 8 mins structured individual counselling on smoking cessation at baseline by occupational physician, + further contacts at 2 days, 15 days and 3m. Grade I (Fagerstrom score < 5) counselling only. Grade II (Fagerstrom score 5 - 7) 8 wks x 14 mg nicotine patches. Grade III (Fagerstrom score > 7) 4 wks x 21 mg, 4 wks x 14 mg, 4 wks x 7 mg. Lower grade interventions could be upgraded if necessary. Participants kept records of progress, withdrawal symptoms, adverse events; weight and tobacco consumption were checked at specified intervals.
2. Control: minimal (30 - 60 secs) sporadic unstructured advice, usually at annual medical check up.
OutcomesContinuous abstinence (7-day PP at each assessment) at 12m.
Validated at each assessment by expired CO ≤ 10 ppm.
Type of intervention4. PHARMACOLOGICAL
NotesThis trial was added to the 2005 update.
Secondary outcomes were: change in tobacco withdrawal symptoms, and weight changes.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"The randomisation list was simple, computer generated, and independent for each study centre".
Allocation concealment (selection bias)Low risk"a sealed opaque envelope".
Blinding of outcome assessment (detection bias)
All outcomes
High risk"The trial was open" (i.e. unblinded).
Incomplete outcome data (attrition bias)
All outcomes
Low riskMinimal losses to follow-up (1 lung ca death).
Selective reporting (reporting bias)Low riskAll expected outcomes reported.

Schröter 2006

MethodsCountry: Germany
Setting: 4 worksites
Design: RCT, sessions allocated randomly to standard behavioural (SB) or relapse prevention (RP) programmes.
Participants79 workers, mean age 40, 58% men, mean cpd 24, mean FTND score 5.
Interventions

6 x 90-min sessions over 8 wks, group counselling + NRT if wanted. First 2 sessions same, then:

1. SB: psycho-educational, self monitoring, environmental cue control, problem-solving, behavioural control strategies, operant conditioning, social support.

2. RP: functional analysis of high-risk situations, planning for them, coping strategies, self monitoring, noting triggers.

OutcomesSelf-reported CA and PPA at 1m and 12m.
Type of intervention1. Intensive behavioural: GROUPS
Notes12m non-responders were phoned for smoking status.
SB participants were given 'rescue' RP training when necessary, so separation of interventions not guaranteed.
New for 2008 update.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated.
Allocation concealment (selection bias)Unclear risk"Researchers randomized the sessions".
Blinding of outcome assessment (detection bias)
All outcomes
High riskPerformance bias: Relapsers in the standard behavioural group were given "rescue" RP when necessary (numbers not reported).
Incomplete outcome data (attrition bias)
All outcomes
High risk45/79 did not provide full follow-up data.
Selective reporting (reporting bias)Unclear risk%s only, not raw data.

Shi 1992

MethodsCountry:USA
Setting: 9 Pacific Gas and Electric (PG&E) worksites, allocated to 4 levels of intervention.
Design: Quasi-experimental, random assignment of worksites. Sites were blinded to other intervention conditions. 
Participants2887 workers across 9 sites at baseline HRA survey (69% of eligibles). At 2-yr follow-up 1998 (48%) were surveyed. Cross-sectional, not cohort surveys.
> 40% of participants were manual workers, 25 - 31% clerical, 15 - 21% managerial and 12 - 16% technical staff.. 74 - 79% male, > 70% aged 30 - 49. 
Interventions1. (3 sites, 1372 participants): HRA (height, weight, smoking, BP, cholesterol, HDL levels) at start and end of programme, + a bi-monthly health newsletter (counts as control group).
2. (2 sites, 1083 participants): As 1, + health resources centre and free self-care booklets.
3. (2 sites, 1016 participants) As 2, + behaviour change workshops and a divisional HealthWise social support team.
4. (2 sites, 693 participants): As 3, + case management programme for high-risk participants (the 15% with the highest risk scores) and an environmental policy (space, smoking policies, incentives, health fairs) 
OutcomesSmoking prevalence at 2-yr follow-up in all 4 intervention groups. Self report 'current smoker' at HRA; no biochemical confirmation.
Type of intervention8. COMPREHENSIVE
NotesThis trial was added to the 2005 update.
This is the HealthWise Stepped Intervention Study (HSIS). Level 4 sites were preselected by PG&E management (non-random) and were significantly smaller than the other levels, reflecting the expense of the Level 4 interventions 
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated.
Allocation concealment (selection bias)High risk"divisions were then randomly assigned"; Level 4 companies preselected by PG&E as small and cheaper to administer.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskDrop-outs recorded as % reduced, but not consistent cohort.
Selective reporting (reporting bias)Unclear riskQuit rates not available, as results reported as prevalence surveys.

Shimizu 1999

MethodsCountry: Japan
Setting: Omihachiman city office
Design: RCT
Participants53 volunteer smokers
Interventions1. Intervention group received intensive education (i.e. the effect of smoking on health, the beneficial aspects of quitting smoking, how to stop smoking and how to deal with the withdrawal symptoms) for 5m, group lectures (twice) and individual counselling (3 times).
2. Control group had no special treatment for 1st 5m
OutcomesSelf-reported and validated using expired air CO concentration.
Type of intervention8. COMPREHENSIVE
NotesOther outcomes included predictors of cessation success.
Data were derived from abstract only
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear riskNot stated
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNot stated
Selective reporting (reporting bias)Unclear riskNot stated

Sorensen 1993

MethodsCountry: USA
Setting: 8 worksites in Bloomington, Minnesota
Design: Cluster-randomized trial.
ParticipantsIntervention worksites (I): 1885 workers
Comparison sites (C): 1479 workers. 39% smoked at baseline in I and 31% in C worksites
Participation rate: 12% of smokers (range 8 - 29% by site); 3.7% of nonsmokers participated in classes to assist quitters.
InterventionsThe 3m intervention included consultation for employers on the adoption of a non-smoking policy, training for nonsmokers to provide assistance to smokers attempting to quit, and cessation classes for smokers
OutcomesQuit rate, self-reported (an attempt was made to collect saliva samples for analysis for cotinine). Baseline survey of all employees was conducted 9m before intervention, companies then randomized, then 3m intervention period, 1m and 6m after the completion of intervention.
Evaluation period: 6m
Type of intervention8. COMPREHENSIVE
NotesAnalyses were by individuals for some outcomes, although randomization was by worksite.
The study area had been an intervention site for the Minnesota Heart Health Program, and outcomes may not be generalizable.
Other outcomes included nonsmokers' support for quit attempts, co-worker requests not to smoke, co-workers' non-smoking, number of quit attempts.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"randomly assigned", "randomized to treatment and control conditions".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNot reported
Selective reporting (reporting bias)Unclear riskNot clear

Sorensen 1996

MethodsCountry: USA
Setting: 108 worksites in 16 US states
Design: Randomized matched-pair trial, using cross-sectional surveys at baseline and 2-yr follow-up
Participants108 worksites with over 28,000 employees ( 49 - 1700 workers per site). Participation rate 72%, Av age 41, 77% men, 92% white.
Only 3 of the 4 study centres (84 sites) measured changes in smoking, as the 4th centre sites (Florida) had smoking bans already in place.
InterventionsEach workplace had an employee as co-ordinator, and an employee advisory board.
1) Individual core interventions: Process included a kickoff event, interactive activities, posters and brochures, self assessments, self-help materials, campaigns and contests, and direct education through classes and groups.
2) Environmental core interventions:
Consultation on smoking policy, changes in cafeteria and vending machine food, and additional nutritional education.
Control sites had results of employee survey, and in some cases an optional minimal intervention of posters and newsletters.
OutcomesSelf-reported smoking cessation, without biochemical validation. 6m abstinence at follow-up, smoking prevalence.
Type of intervention8. COMPREHENSIVE
Notes

This is the Working Well Trial.
Randomization and analysis were both based on worksite.
Other outcomes were dietary fat reduction, fibre intake and fruit and vegetable consumption.
Some control sites had minimal interventions such as posters and brochures.

The Working Well trial generated a nested cohort study, the WellWorks Trial, which examined dietary and smoking changes stratified by job type at the Massachusets worksites. See Sorensen 1998.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"work sites were stratified, matched into pairs, and randomly assigned within pairs"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
High riskNo baseline prevalence data, so losses not calculable
Selective reporting (reporting bias)Unclear riskInsufficient data to derive quit rates

Sorensen 1998

MethodsCountry: USA
Setting: 24 mainly manufacturing worksites in Massachusets, randomized into 12 pairs, and all thought to be using known or suspected carcinogens.
Randomization was by worksite, but analysis was by individual. Analysis in this paper was cohort-based
Participants5914 (61%) of sampled employees responded at baseline, and 5406 (62%) at 2-yr follow-up.
The cohort who responded to both surveys was 2658 employees (699 smokers and recent quitters).
Interventions3 elements of intervention:
1) Joint worker-management programme planning and implementation
2) Consultation by project staff with management on environmental changes, inc tobacco control policies, healthy foods, occupational hazard reduction
3) Health education programs targeting individual behaviours in the risk factor areas.
OutcomesSelf-reported abstinence for 6m before final survey.
No biochemical validation
Type of intervention8. COMPREHENSIVE
NotesThe WellWorks Study is a nested component of the Working Well trial (Sorensen 1996), but, unlike that trial, attempted to integrate health promotion and health protection interventions, and is therefore assessed separately.
Other outcomes included fat, fibre and fruit and vegetable consumption, and differences between blue- and white-collar workers in all outcomes.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"worksites were matched into 12 pairs... One work site in each pair was then randomly assigned"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNo report of losses
Selective reporting (reporting bias)Low riskExpected outcomes reported

Sorensen 2002

MethodsCountry: USA
Setting: 15 manufacturing sites, probably handling hazardous chemicals, in Massachusetts.
Design: RCT, randomized by worksite, but analysed by individual employee.
Participants9019 employees (80%) across 15 sites. Mean workforce size 741 employees. Responders in the control groups were younger, more likely to be women, less educated, less likely to be white, and less likely to be hourly-paid rather than salaried.
Interventions1. Control [8 sites] had Health Promotion (HP) intervention, i.e. consultation to management on tobacco control policies, catering and cafeteria policies, and programmes aimed at individuals, including self assessment with feedback, self-help activities, contests, demonstrations and displays, opportunities to try behaviours and goals, and group discussions.
2. Experimental Group [7 sites] (HP/OHS = health promotion with occupational health and safety) had the same elements as the Control sites, plus management recommendations to reduce occupational hazard exposure. For individuals, occupational health and safety training was added to the tobacco and nutritional elements of the control programme.
OutcomesQuit rates (PP) at 6m, reported by cross-sectional survey and for the smoking cohort.
Self report only, no biochemical validation
Type of intervention8. COMPREHENSIVE
NotesThis is the Wellworks-2 Trial, targeting particularly blue collar workers. Analyses were cross-sectional and cohort.
Other primary outcomes were nutrition and perceived exposure to occupational hazards.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"Worksites were randomly assigned by the study biostatistician using a process conducted independently from the intervention team"
Allocation concealment (selection bias)Low risk"Worksites were randomized within blocks..."
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low riskDrop-outs reported, and separated from the "embedded cohort" who replied to all surveys
Selective reporting (reporting bias)Low riskAll expected outcomes reported

Sorensen 2007

MethodsCountry: USA
Setting: Phone-based and mailed info, targeted at members of LIUNA (construction workers union).
Design: RCT, no details given
Participants674 workers (354 intervention and 320 control*) completed baseline survey, and 582 (188 smokers [= current or quit within last 6m]) at 6m follow-up. 94% men, mean age 40, smoking prevalence I:45%, C:40%.
Interventions3m programme to increase fruit & veg consumption and quit smoking.
Intervention: (i) Phone-based counselling, up to 4 calls in 3m.
(ii) Mailed tailored feedback. (iii) 6 mailings of targeted info. (iv) NRT if requested.
Control: Nothing during programme, but all targeted written info at study end.
OutcomesSelf-reported 7-day PPA at 6m, no verification.
Increased fruit & veg consumption.
Type of intervention8. COMPREHENSIVE
NotesTools for Health programme; specifically targeted blue-collar workers.
* data supplied by authors
New for 2008 update.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear risk"survey respondents agreeing to participate were randomly assigned to one of two conditions"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk92 lost to follow-up
Selective reporting (reporting bias)Unclear riskAll expected outcomes reported

Sutton 1987

MethodsCountry: UK
Recruitment: Worksite primary care clinic in UK retail company (employees 3253)
Design: RCT, no details of method
Participants270 participants invited out of 334 who expressed an interest
Av age: 34, 70% women
av cpd 15.5
Interventions1. Nicotine gum (2 mg) at least 4 boxes, duration not stated. (172 people)
2. Non-intervention control group (no placebo) of 64 continuing smokers
Low level of support
OutcomesSustained abstinence at 12m; Validation: expired CO
Type of intervention4. PHARMACOLOGICAL
NotesSlight contamination of intervention group, as 4 control group members were moved at their own request into the intervention group.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High risk4 controls moved at their own request into intervention group
Allocation concealment (selection bias)High risk"a randomly selected 270 were sent a personal invitation"; the remaining 64 who had expressed an interest became the control group
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
High riskLosses reported, but not by group
Selective reporting (reporting bias)Unclear riskAbsolute numbers unclear

Sutton 1988a

MethodsCountry: UK
Setting: Company A with occupational health programme near London
Design: RCT: cessation motivation vs seat belt video groups
Participants77 in videotape conditions (33 for smoking video, 44 for seatbelts video), 55 non-participant smokers (no-treatment control group).
InterventionsTrial was described to company as a 'health information programme', and was open to all employees, whether or not they smoked.
1. 25-minute video 'Dying for a Fag' (DFF) plus a cessation booklet, the Health Education Council's 'The smoker's guide to non-smoking'
2. 25-minute video on seatbelt use, + a leaflet about seatbelts
3. Smokers who chose not to participate - no videos or information
OutcomesSelf-reported PP smoking cessation at 3m and 1yr with CO validation < 10 ppm
Type of intervention3. SELF-HELP
NotesAlthough all 4 trials (a-d) are of similar design, and are reported in a single paper, we have treated them here as 4 separate RCTs.
Cash incentives were offered at baseline and at 12m follow-up to boost questionnaire response rates.
The authors also present a 4-study pooled analysis, which failed to detect signficant differences in cessation rates.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskSee below
Allocation concealment (selection bias)Unclear risk"Sessions were randomly assigned to videotapes"
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low risk% of drop-outs reported, and ITT analysis performed
Selective reporting (reporting bias)Low riskAll expected outcomes reported

Sutton 1988b

MethodsCountry: UK
Setting: Company B with occupational health programme near London
Design: RCT: cessation motivation vs cessation motivation plus confidence boosting vs political aspects of tobacco video groups
Participants150 in videotape conditions (46, 50 and 54 in the 3 groups), + 374 non-participant smokers
InterventionsTrial was described to company as a 'smoking education programme', and was open only to smokers.
1. 25-minute video 'Dying for a Fag' (DFF) plus a cessation booklet, the Health Education Council's 'The smoker's guide to non-smoking'
2. DFF with additional sequence to boost the confidence of those making a quit attempt (DFF+C)
3. 'Licence to Kill', on the political aspects of smoking (LTK).
4. Smokers who chose not to participate - no videos or information
OutcomesSelf-reported PP smoking cessation at 3m and 1yr with CO validation < 10 ppm
Type of intervention3. SELF-HELP
NotesCash incentives were offered at baseline and at 12m follow-up to boost questionnaire response rates.
The authors also present a 4-study pooled analysis, which failed to detect significant differences in cessation rates.
Although the cessation rates appear to be significantly better in this study than in the other 3, the authors point out that follow-up was around New Year, when many people try and stop anyway, and may also have been influenced by the concurrent BBC series 'So you want to stop smoking'
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskSee Sutton 1988a

Sutton 1988c

MethodsCountry: UK
Setting: Company C with occupational health programme near London
Design: RCT : cessation motivation vs cessation motivation minus a gory sequence vs. advertising aspects of tobacco videotapes groups
Participants197 in videotape conditions (56, 67 and 74 in the 3 groups) + 226 non-participant smokers
InterventionsTrial was described to company as a 'smoking education programme', and was open only to smokers.
1. 25-minute video 'Dying for a Fag' (DFF) plus a cessation booklet, the Health Education Council's 'The smoker's guide to non-smoking'
2. DFF with graphic 'shock' sequence about diseased lungs edited out, to lower fear element (DFF-G)
3. 'The Tobacco War', on the advertising aspects of smoking (TW).
4. Smokers who chose not to participate - no videos or information
OutcomesSelf-reported PP smoking cessation at 3m and 1yr with CO validation < 10 ppm
Type of intervention3. SELF-HELP
NotesCash incentives were offered at 12m follow-up to boost questionnaire response rate.
There were no differences between the video and non-participant groups in long-term abstinence .
The authors also present a 4-study pooled analysis, which failed to detect signficant differences in cessation rates.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskSee Sutton 1988a

Sutton 1988d

MethodsCountry: UK
Setting: Company D with occupational health programme near London
Design: RCT: cessation motivation vs another cessation motivation vs advertising aspects of tobacco videotapes groups
Participants179 in videotape conditions (62, 59 and 58 in 3 groups) + 360 non-participant smokers
InterventionsTrial was described to company as a 'smoking education programme', and was open only to smokers.
1. 25-minute video 'Dying for a Fag' (DFF) plus a cessation booklet, the Health Education Council's 'The smoker's guide to non-smoking'
2. "Smoker's Luck", on a continuing smoker suffering from advanced smoking-related disease (SL)
3. 'The Tobacco War', on the advertising aspects of smoking (TW).
4. Smokers who chose not to participate - no videos or information
OutcomesSelf-reported PP smoking cessation at 3m and 1yr with CO validation < 10 ppm
Type of intervention3. SELF-HELP
NotesThere were no differences between the video and non-participants groups in long-term abstinence.
Cash incentives were offered at baseline and at 12-month follow-up to boost questionnaire response rates.
The authors also present a 4-study pooled analysis, which failed to detect signficant differences in cessation rates.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskSee Sutton 1988a

Sutton 1988e

MethodsCountry: UK
Recruitment: Worksite primary care clinic (employees 3253)
Design: RCT, no details of method
Participants161 adult smokers who were still smoking after 3m of a videotape smoking cessation programme. Av cpd 15 - 19
Interventions1. Nicotine gum (2 mg) for up to 12w
2. Non-intervention control group (no placebo).
Low level of support
OutcomesValidated long-term abstinence at 12m
Validation: expired CO
Type of intervention4. PHARMACOLOGICAL
NotesParticipants are the non-quitters at 3m from Sutton 1988d
5/82 control subjects asked for and received treatment. One was a long-term abstainer, and is classed as a control group success.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)High risk"randomly divided into two groups", but 5 control subjects requested treatment.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low riskNo losses to follow-up
Selective reporting (reporting bias)Low riskAll expected outcomes reported

Tanaka 2006

MethodsCountry: Japan
Setting: 12 companies (500 - 1000 employees each)
Design: Matched pairs controlled study (randomization intended but not feasible).
ParticipantsInt/Cont: 1382/1736 current smokers, 94%/97.4% men, 92.9%/95.7% blue-collar workers, 66.1%/61.5% smoke > 20 cpd. Significant differences between groups on age, gender, occupation type, cpd, controlled for in analysis.
71.6%/73.2% in precontemplation; 35.1%/34.5% had made at least one previous quit attempt.
InterventionsIntervention: 1. Posters, newsletters, website, advertising the cessation campaign and stages of change model.
2. Worksite smoking cessation programme, conducted by worksite nurse using research team materials, giving (a) 5 brochures on stages of change, (b) 4 counselling sessions + NRT if requested, (c) award to winner among abstainers. 6-wk programme, run 5 times over 36m.
3. Advice re secondhand smoke, and designation of smoking areas.
4. Regular site visits by member of research team.
Control: Standard annual health checks.
Participation rate was 9% across all sites.
OutcomesSustained 6m abstinence at 12m, 24m, 36m, not biochemically verified.
Movement through stages of change, cost-benefit analysis.
Type of intervention8. COMPREHENSIVE
NotesNew for 2008 update (previously an excluded study)
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskN/A
Allocation concealment (selection bias)High riskNot randomized (opposition from the companies)
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskDrop-out rates reported (26.4% over 3 years)
Selective reporting (reporting bias)Unclear riskAll expected outcomes reported

Terazawa 2001

MethodsCountry: Japan
Setting: Occupational health clinic
Design: RCT; details of randomization not described
Participants228 smokers, randomized to intervention (117) or control (111). Average age 39, av cpd 23; 50% had made previous quit attempts.
InterventionsBaseline questionnaire during routine health check up, with CO and urinary metabolites measured and reported back.
1. Intervention: Stage-matched counselling (15 - 20 mins) by trained nurses, + 4 follow-up phone calls for those prepared to set a quit date.
2. Control: baseline questionnaire and usual care.
OutcomesContinuous abstinence at 6m and 12m. Validated by CO ?
Type of intervention2. Intensive behavioural: INDIVIDUAL COUNSELLING
NotesThis trial was added to the 2005 update
25 smokers in the intervention group set a quit date and received the follow-up calls.
Data were derived from abstract only
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot stated
Allocation concealment (selection bias)Unclear riskNot stated
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNot stated
Selective reporting (reporting bias)Unclear riskNot stated

Volpp 2009

MethodsCountry: USA
Setting: Multiple worksites of General Electric Energy Company
Study design: RCT
Participants878 smokers, randomized to Int (436) or control (442). Av age 45, 65% men, av 20 cpd, 25% high school or lower, 65% income > 500% of poverty level. Motivation to quit not required. No sig baseline diffs between groups on any demographic variables.
Interventions

All pts given information on local community-based SC services, + received standard employee benefits, e.g. physician visits, SC pharmacotherapies. All received USD 20 per telephone interview at baseline and at 3 follow-ups, plus USD 25 per confirmatory sample returned.

Int: Told they would receive USD 100 for completing an SC course, USD 250 for confirmed abstinence at 6m, and USD 400 for confirmed sustained additional 6m abstinence.

OutcomesProlonged abstinence at 9 or 12m. Those not abstinent at 3m were retested at 6m, and followed from then if abstinent. All abstinent at both follow-ups were assessed again 6m later, i.e. at 15 or 18m.
9 - 12m endpoint used in 6m MA, and 15 - 18m endpoint in 12m MA.
Validation: Cotinine by saliva or urine
Type of intervention7. INCENTIVES
NotesNew for 2014 update;
Funded by CDC grants RO1 DP000100-01 and RO1 DP001168-01, and Pennsylvania Department of Health.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"performed in permuted blocks of four", stratified by level of smoking (+/- 2 packs per day), income and worksite.
Allocation concealment (selection bias)Low risk"assignments were concealed until all eligible criteria had been entered"
Blinding of outcome assessment (detection bias)
All outcomes
High risk"blinding could not be maintained ... because of the nature of the intervention"
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskDrop-outs and losses fully reported
Selective reporting (reporting bias)Unclear riskAll expected outcomes reported

Willemsen 1998

MethodsCountry: Holland
Setting: 4 worksites (chemical, telecommunication, public transport and local government) and 4 other similar worksites
Design: cluster-randomized trial
Participants279 employees at intervention sites and 234 employees at comparison sites
Average age: 41 years
75% men
Interventions1. Comprehensive programme (self-help manuals, group courses, a mass media campaign, smoking policies and a 2nd-yr programme)
2. Minimal intervention (self-help manuals only).
OutcomesSelf-reported smoking cessation and saliva cotinine estimation
Type of intervention8. COMPREHENSIVE
NotesAnalysis of light vs heavy smokers suggests greater efficacy among heavy smokers (P values not given).
Other outcomes included relapse rates, the effectiveness of a 2nd-yr programme.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskN/A
Allocation concealment (selection bias)High riskWorksites self-selected involvement
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskLosses reported for SC group course participation, and ITT analysis done
Selective reporting (reporting bias)Unclear riskSome expected outcomes reported

Windsor 1988

  1. a

    ALA: American Lung Association
    av: average
    BMI: body mass index
    BP: blood pressure
    CO: carbon monoxide
    cpd: cigarettes per day
    ETS: environmental tobacco smoke
    FTND: Fagerström Test for Nicotine Dependence
    h: hour
    HDL: high density lipids
    HRA: health risk assessment
    inc: Including
    I: intervention; C: control
    m: month
    MI: motivational interviewing
    NRT: nicotine replacement therapy
    NTQ: nicotine tolerance questionnaire
    PEF: peak expiratory flow
    PPA: point prevalence abstinence
    ppm: parts per million
    RCT: randomized controlled trial
    SC: smoking cessation
    SoC: stage of change
    S-H: self help
    vs: versus
    w: week
    yr: year (s)

MethodsCountry: USA
Recruitment: University of Alabama employees volunteering for a quit smoking programme
Design: randomized 2 x 2 factorial trial
Participants378 smokers
Av. age 37, av cpd 23 - 27
Therapist: health visitor
InterventionsAll groups received a 10-minute session of brief advice
1.+ S-H manuals (n = 95)
2. +S-H and another session of counselling (20 - 30 mins) with skills training, buddy selection and a contract (n = 94)
3. as 1, with monetary awards for cessation (n = 95)
4. as 2, with monetary rewards for cessation (n = 94)
OutcomesAbstinence at 1 yr (sustained at 6w, 6m & 1 yr)
Validation: saliva thiocyanate < 100 ng/ml at all follow-ups
Type of intervention2. INDIVIDUAL COUNSELLING/ INCENTIVES
NotesOther outcomes included some cost-benefit analysis, including efficacy of incentives..
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"a computer-generated assignment system"... before the baseline interview
Allocation concealment (selection bias)Low risk"400 employee group assessment labels were placed in separately sealed envelopes"; "the next sequentially numbered envelope".
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot stated
Incomplete outcome data (attrition bias)
All outcomes
Low riskLosses to follow-up reported; 7 quitters from Groups 2&4 lost to follow-up and counted as smokers
Selective reporting (reporting bias)Unclear riskGroups pooled and not reported separately

Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion
Addley 2001Observational study, no control worksites. Smoking was one of a number of lifestyle changes surveyed over a 3-year period, by a follow-up postal survey 6 months after assessment.
Armitage 2007RCT for smoking reduction; 2m duration
New for 2008 update.
Baile 1991Follow-up only 4 months. Evaluated the impact of a hospital smoking ban with no report of cessation programmes.
Barbeau 2006Pre/post study, no control group, assessment at 5m
New for 2008 update.
Bertera 1990Non-randomized. Evaluated the relative efficacy and cost effectiveness of a stop smoking clinic versus self-help kit in the workplace
Borland 1991bExamined predictors of smoking cessation attempts not cessation rates after the introduction of workplace smoking bans.
Borland 1995One group post-test only. Surveyed smokers 2 years after a total workplace ban.
Brenner 1992Population-based survey, to assess the effects of workplace smoking bans and cessation rates, expressed as a quit ratio
Brenner 1994One group, post-test only. Evaluated smoking regulations at the workplace and smoking behaviour in Southern Germany.
Brigham 1994Follow-up for only 4 weeks. Examined the effects of a restricted worksite smoking policy on employees who smoke.
Broder 1993Pre- and post-ban surveys on 3 buildings (137 workers), to assess air quality and physical symptoms of ETS. Prevalence was not a primary outcome, but was reported as unchanged between the 2 surveys
Bunger 2003Description of a cardiovascular risk reduction intervention in a power plant; no control or comparison site
Burling 1989Trial of nicotine fading + self-help materials versus self-help materials alone; originally an included study, but classified as excluded for 2014 update.
Burling 1994Descriptive report of a computer-directed programme for smoking cessation treatment. Previous reported outcome data from a minimal intervention and intensive stop smoking treatment are presented.
Burling 2000Trial of ALA self-help programme versus an internet-based self-help programme; originally an included study, but classified as excluded for 2014 update.
Busch 2005Observational study of 2 German factory interventions.
New for 2008 update.
Campbell 2000Cross-sectional survey of 859 women in 9 North Carolina worksites, to assess health behaviours, risks and desire to change behaviour. A population-based survey, with no control group or intervention.
Choi 20076-wk RCT of patches for reducing craving.
New for 2008 update.
Conrad 1996Non-randomized. Evaluated exposure to a worksite health-promoting environment as an aid to smoking cessation.
Cooreman 1997Eight years had elapsed between surveys. Evaluated the impact of a smoking ban in a large Paris hospital
Cornfeld 2002Large cohort study, not a controlled intervention trial
Dalsey 2009Survey response to implementation of a smoke-free policy. New for 2014.
Daughton 1992One group, no pre-test. Evaluated the effect of a smoking ban with partially subsidised cessation programmes.
Dawley 1984Non-randomized. Evaluation of a smoking cessation treatment programme of 10 x 1-hour sessions.
Dawley 1993Follow-up for only 4 months. A programme of smoking control in one company versus a smoking cessation class in a second company.
Eisner 1998Outcome not smoking cessation but bartenders' respiratory health. Evaluated the respiratory health of bartenders before and after legislative prohibition of smoking in all bars and taverns by the state of California.
Emont 1992Outcome not smoking cessation. Evaluated the effectiveness of incentives as an aid to recruitment.
Eriksen 2005Survey of Norwegian nurses' smoking
New for 2008 update.
Etter 1999Follow-up for only 4 months. Evaluated short-term impact of a University-based smoke-free campaign.
Farkas 1999Non-workplace for part of study. Evaluated the association of household and workplace smoking restrictions with quit attempts, 6-month cessation and light smoking.
Farrelly 1999Cross-sectional not pre-post-test. Estimated the impact of workplace smoking restrictions on the prevalence and intensity of smoking among all indoor workers.
Fine 2004Comparison of CHD risk factor interventions and musculo-skeletal interventions in Welsh workplaces. Outcome was acceptability and feasibility in small workplace.
New for 2008 update.
Franchin 20112 workplace health promotion programmes, with a 'quit & win' contest as the tested intervention. New for 2014.
Glasgow 1997Data from a population-based survey of adult smokers who completed surveys in 1988 and 1993, as part of the COMMIT trial.
Gomel 1993bFollow-up for only 6 weeks. Examined the short-term effects of a workplace smoking ban on indices of smoking, cigarette craving, stress and other health behaviours in 24 employees.
Gottlieb 1990aNon-randomized. 3-stage study included a baseline survey, an assessment of the effects of competition on recruitment to a self-help cessation programme and examination of the outcome of the cessation programme.
Graham 2007Observational study, no control group
New for 2008 update.
Gritz 1988Non-randomized. Evaluation of a self-help smoking cessation programme for registered nurses.
Hagimoto 2007Assessment of counsellors' skills and success rates in 6 Japanese worksites.
New for 2008 update.
Hailstone 2005Evaluation, no control group.
New for 2008 update.
He 1997Follow-up for only 3 weeks. Examined the effects of acupuncture on smoking cessation or reduction for motivated smokers.
Heloma 20019 Finnish worksites surveyed before and after legislation to restrict ETS; not a controlled trial
Helyer 1998Non-randomized. Evaluated the effectiveness of a worksite smoking cessation programme in the military.
Hope 1999Non-randomized study, with no control or comparison group, and short follow-up (timing not stated). Surveyed 5 workplaces before and after a 1-year health promotion campaign, targeting multiple health behaviours, including smoking. Primarily interested in gender and social class differences
Hotta 2007Evaluation study, no control group.
New for 2008 update.
Hudzinski 1994Outcome was daily cigarette consumption, cessation rate not reported. Study was designed to assess changes in employee health, particularly weight gain and CO levels, and smoking behaviour.
Humerfelt 1998Community-based, not workplace. Evaluated the effects of postal smoking cessation advice in smokers with asbestos exposure and /or reduced forced expiratory volume in 1 second.
Hunt 2003aThe SMART study; RCT, targeting employed adolescents rather than adults.
Hunt 2003bHealthy Directions - Small Businesses study; RCT, but smoking cessation was not the target intervention, and was offered in both intervention and control sites (= 24).
Hutter 2006Evaluation of Allen Carr programme; no control group.
New for 2008 update.
Hwang 2012Observational Korean study of a step-wise workplace cessation programme. New for 2014.
Izuno 1990Non-randomized. Examined the factors critical to behaviour modification with respect to smoking cessation at worksites.
Jason 1990Non-randomized. A cessation programme with incentives and competition offered in 1 company, compared to a control company.
Jeffery 1988Trial of cessation versus reduction or cessation; originally an included study, but classified as excluded for 2014 update.
Kadowaki 200410-year Japanese programme of annual small-scale smoking cessation interventions; assessed at 2 months, but primary outcome was overall prevalence after 10 years. Controlled trial, but not randomized.
Kinne 1993Population-based telephone survey of 1228 employed adults to assess impact of worksite smoking policies.
Klesges 1986Non-randomized. A smoking cessation programme offered in 5 companies, with and without competitions for participation and cessation.
Koffman 1998Not a randomized study, as one of the 3 participating worksites refused to be randomized.
Kornitzer 1987

Testing variable doses of NRT, without a non-cessation control group.

Originally an included study, but counted as excluded for 2014 update.

Kunitsuka 2002Survey of post-intervention multiple lifestyle changes, including number of cigarettes smoked. No control group used.
Longo 1996Not pre-post-test evaluation but post-ban quit ratio. Examined the impact of workplace smoking bans on smoking behaviour of employees.
Longo 2001Not pre-post-test. Examined the long-term impact of workplace smoking bans on employee smoking cessation and relapse.
Lowe 1987Cessation was not an outcome of interest. Evaluated method of contact (phone vs letter) as an aid to recruitment.
Maheu 1989Non-randomized. 2 worksites offered a multicomponent behavioural programme with nicotine gum. Additional competition in 1 site.
Makrides 2008RCT of a comprehensive worksite intervention, reporting smoking reduction; author contacted, but cessation rates not available. New for 2014.
Matson-Koffman 1998Non-randomized. Evaluated the effectiveness of a multicomponent smoking cessation programme supplemented by incentives and team competitions.
McMahon 2001Small non-randomized pilot study, based on stages of change model, to compare expert systems, group support and self-help manuals.
McMahon 2002Happy Heart at Work programme; 10-yr evaluation, without a control group
Musich 2003Survey of changes in risks among GM employees; not a controlled trial
Muto 1998Non-randomized. Evaluated the effectiveness of a smoking cessation programme known as 'Smoke Busters'.
Nepps 1984Non-randomized. Evaluation of a minimal contact smoking cessation programme at the worksite.
Nerín 2002Evaluation of an anti-smoking programme, without a comparison worksite
Nerín 2005Evaluation study, no control group.
New for 2008 update.
O'Connell 2006Evaluation study, no control group.
New for 2008 update
Offord 1992One group, post-test only. Evaluated the effect of a smoking ban, with no-cost nicotine dependence treatment.
Olive 1996One hospital had pre-test data. Evaluated changes in employee smoking behaviour after implementation of restrictive smoking policies.
Olsen 1990Non-randomized. Evaluation of a smoking cessation incentive programme for Dow chemical employees in the USA.
Olsen 1991Non-randomized. A 5-year evaluation of a smoking cessation incentive programme for chemical employees.
Ong 2005Cost effectiveness rather than efficacy evaluation.
New for 2008 update.
Park 2007Korean controlled before-and-after study; probably too short (5-day programme); no further information from authors. New for 2014
Patten 1995Population-based telephone survey of 1844 Californian adult indoor workers, to assess changes in smoking status and cigarette consumption, related to whether or not their workplace was smoke-free, and for how long the ban had been in place..
Pegus 2002The Heart At Work programme. Smoking prevalence was measured, but was not an intervention outcome
Prior 2005Cohort study, no comparison worksite.
New for 2008 update.
Richmond 1985Non-workplace setting. A smoking cessation programme for use in general practice
Rosenstock 1986Post-test only. Evaluated a non-smoking policy in a health maintenance organization
Roto 1987Non-workplace setting for half of the participants. Evaluated nicotine gum and advice versus advice only for smoking cessation.
Ryan 2002594 employees at a UK pharmaceutical company (GSK) attempted to quit with bupropion, and were followed up at 6 months. Not an RCT.
Schlegel 1983Non-randomized. Evaluation of 'BUTT OUT' , a quit smoking programme developed specifically for the Canadian Armed Forces.
Scott 1986Non-randomized. Nurses in different units offered cessation treatment or a waiting list control. 29 participants.
Shipley 1988Non-randomized. Determined the effect of a smoking cessation programme compared with health screening on employee smoking.
Sloan 1990Non-randomized. Evaluated cessation and relapse in a year-long workplace quit-smoking contest.
Sorensen 1991One group post-test only . Evaluated the impact of a restrictive smoking policy with free onsite smoking cessation classes.
Sorensen 2010Not randomized, pre-test/post-test. New for 2014.
Stoddard 2005RCT of teenagers (aged 15 - 17) working part-time, many still in school.
New for 2008 update
Stoddard 2008RCT of supplementing an online smoking cessation service with a 'bulletin board'. New for 2014.
Sun 2009Not set in a workplace, though testing employment as a predictor of successful cessation. New for 2014.
Terry 2010Study of enrolment and retention rates in a comprehensive worksite health promotion programme. New for 2014.
Ullén 2002Evaluation of a Swedish hospital smoking ban, but without a comparison worksite.
Waage 1997Non-randomized. Smoking intervention based on risk communication in subjects at risk of asbestos-related lung cancer.
Wakefield 1996Did not report smoking cessation rate. Compared the reported prevalence and acceptance of bans on smoking among indoor workers in South Australia.
Whitney 1994One group, post-test only. Determined the impact of a smoking cessation programme using NRT as part of a larger wellness programme.
Wilbur 1986Comprehensive health promotion intervention, but not a randomized trial.
Willemsen 1995Non-randomized. Evaluated a smoking cessation intervention for Dutch employees consisting of self-help methods and a group programme.
Willemsen 1999Non-randomized. Examined the impact of a comprehensive worksite smoking cessation programme on employees who do not take part in cessation activities.
Woodruff 1993Results of the 1990 California Tobacco Survey; 11,704 working adults responded. Aim was to assess relationship of worksite policy (or its absence) to smoking status, controlling for demographic factors

Characteristics of studies awaiting assessment [ordered by study ID]

Gao 2010

MethodsRCT in 2 Shanghai workplaces; 2008 - 2009
Participants233 intervention 246 control; mean age 34.7 and 31.1.
InterventionsTobacco control programme based on theory of organizational change.
OutcomesSmoking prevalence, cpd, willingness to accept colleague support, knowledge about smoking and harms; cessation at 6m, cotinine-confirmed.
NotesNo response from authors re smoking cessation rates (denominators),

Characteristics of ongoing studies [ordered by study ID]

NCT01124110 2012

Trial name or titleTobacco Tactics website, worksite-based
MethodsRCT, pilot study.
Participants184 blue-collar operating engineers.
InterventionsTobacco Tactics website vs 1-800-QUIT-NOW telephone support programme, + NRT + counselling.
Outcomes6m cessation rates, cotinine-validated.
Starting date 
Contact informationbump@mich.edu
Notes 

NTR8148 2012

Trial name or titleWeb-based health risk assessment
MethodsCluster-randomized controlled trial
Participants 
InterventionsIndividually-tailored feedback to baseline questionnaire; targeting 5 indicators: physical activity, nutrition, smoking behaviour, alcohol consumption, signs of burnout.
Outcomes6m performance on sum of all 5 indicators.
Starting date 
Contact information 
NotesFunded by ZonMw project number 200310006

Simpson 2000

Trial name or titleAustralian National Workplace Health Project
MethodsCluster-randomized trial, 20 worksites, 2x2 factorial design
ParticipantsEmployees in participating worksites. 2498 completed baseline survey, 2082 completed health risk appraisal
InterventionsSocio-behavioural and environmental intervention, for physical activity, healthy eating, smoking and alcohol
OutcomesBehaviour change at 1 and 2 yrs
Starting dateNK
Contact informationjudy.simpson@sydney.edu.au
NotesIncluded in 2005 update; no further info for 2008 update, or for 2014 update

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