• Clinical practice;
  • motivation;
  • predictors;
  • quit attempts;
  • smoking;
  • smoking cessation

Awareness of factors shaping smokers phenotypes is important for identifying potential relapsers and to improve success in smoking cessation. Identifying individual characteristics that predict success could help to match smokers with a strategy more likely to help them quit. This knowledge could help to optimize health care resources and refine state funded tobacco policies.

Delivering on these aspirations requires an improved understanding of success factors in well characterized cohorts of smokers. Currently, no accurate determinants of smoking cessation have been found. Socio-demographic features, psychological factors, smoking history, and severity of nicotine dependence have been extensively investigated both in aided and unaided smoking cessation, but results are not clear-cut [1]. Predictors of smoking cessation are derived from very heterogeneous populations, factors usually explored may not be the significant ones, and study outcomes are not always clearly defined.

In our systematic review of predictors of smoking cessation [1], predictors of a quit attempt were not differentiated from those causing sustained abstinence; generally these predictors do not appear to match [2]. In their elegant systematic review of non-intervention prospective studies, Vangeli et al. [3] address this methodological issue by appraising predictors of both quit attempts and quit attempt success in the same population samples. In spite of a high level of heterogeneity between studies, the authors found that past quit attempts and measures of motivation to stop are highly predictive of quit attempts, whereas only measures of dependence are consistently predictive of successful attempts.

One of the most striking findings reported by the authors is the discrepancy between East Asian populations (but not Japan) and westernized societies in popular predictor variables of quit attempt success (i.e. age, longest time off smoking, intention to quit, and confidence of success in quitting). Likewise, surveys that assessed the antismoking climate in the European Union have shown significant dissimilarities in relation to quitting behaviours and smoking attitudes between smokers from different nations [4,5]. Consequently, findings about predictors of smoking cessation cannot be generalized and must take into account, particularly in real-life settings, the socio-cultural and religious traits of smokers in different countries,.

To a large extent, the value of a systematic review depends on the quality and relevance of the existing data. It is unfortunate that the eight studies included in the review placed little emphasis on important dynamic factors that predict relapse. Smoking cessation is a process, and relapse is an ordinary component of this process. Therefore, the predictor variables commonly recorded at baseline may not be very representative of the dynamic psychological and physical changes occurring in the smokers struggling to quit.

For instance, withdrawal symptoms—the main cause for relapse—vary in their intensity and duration from smoker-to-smoker during abstinence [6]. Withdrawal symptoms are believed to peak in the first few days and subside after two to four weeks. For some people, however, the symptoms can last longer [7]. These patients are at the highest risk of relapse. Careful monitoring of withdrawal symptoms by validated questionnaires may detect those patients experiencing elevation of symptoms [8]. Other important dynamic factors that predict relapse include self-efficacy and outcome expectancies of quitting after the start of the quit attempt [9]. Future studies should incorporate evaluation of these important dynamic factors.

This review supports the evidence that measures of dependence are consistently predictive of successful quit attempts. However, given that smoking is much more than the addicting effect of nicotine, the measures of dependence (e.g. FTND)—originally intended for assessing the physical component of cigarette dependence—also assess a behavioural component associated with cigarette smoking. Smoking gestures (e.g. the tactile sensations of the cigarette and other sensations associated with smoking gestures) can play an important part in tobacco addiction as they are usually performed in a predictable, ritualistic manner that acts to signal a mental context shift. When the smoker stops smoking the need for the ritual still exists. This could be an important cause of relapse [10,11]. Thus, in the light of current knowledge about what determines cigarette smoking, FTND has to be considered more a composite (physical plus behavioural) measure of cigarette dependence than a simple measure of tobacco dependence [12].

Our recent research suggests that improved characterization of behavioral sub-phenotypes by Glover-Nilsson Smoking Behavioural Questionnaire (GN-SBQ) can be exploited to improve smoking cessation outcomes [13]. Smokers who were identified by GN-SBQ as being heavily dependent on the behavioural pattern of smoking had a quit rate of 66.7% when using nicotine-free inhalers, compared with 28.3% of the reference group.

The challenging path to successful smoking cessation runs via the discovery of stronger and more relevant determinants of smoking relapse. Without this knowledge, improved phenotypic classification of individuals with a strong desire to quit and personalized management plans for their tobacco dependence will remain just a dream. A research agenda leading to a step-change in discovering and understanding stronger predictors of smoking relapse is the only recipe for success.


  1. Top of page
  2. Declarations of interest
  3. References