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Interventions to enhance adherence to dietary advice for preventing and managing chronic diseases in adults

  1. Sophie Desroches1,2,*,
  2. Annie Lapointe1,2,
  3. Stéphane Ratté1,
  4. Karine Gravel2,
  5. France Légaré3,
  6. Stéphane Turcotte1

Editorial Group: Cochrane Consumers and Communication Group

Published Online: 28 FEB 2013

Assessed as up-to-date: 20 DEC 2011

DOI: 10.1002/14651858.CD008722.pub2


How to Cite

Desroches S, Lapointe A, Ratté S, Gravel K, Légaré F, Turcotte S. Interventions to enhance adherence to dietary advice for preventing and managing chronic diseases in adults. Cochrane Database of Systematic Reviews 2013, Issue 2. Art. No.: CD008722. DOI: 10.1002/14651858.CD008722.pub2.

Author Information

  1. 1

    St-François d'Assise Hôpital, Centre de recherche du Centre hospitalier universitaire de Québec (CHUQ), Québec, Québec, Canada

  2. 2

    Université Laval, Département des sciences des aliments et de nutrition, Québec, Canada

  3. 3

    Université Laval, Département de médecine familiale et d'urgence, Québec, Québec, Canada

*Sophie Desroches, sophie.desroches@fsaa.ulaval.ca.

Publication History

  1. Publication Status: New
  2. Published Online: 28 FEB 2013

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Background

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms
 

Description of the condition

Chronic diseases are defined as diseases of long duration that have generally a slow progression (WHO 2008). The most common chronic diseases include diabetes, cardiovascular diseases (CVD), cancers, asthma, chronic obstructive pulmonary diseases (COPD), arthritis, obesity and renal failure. Considering that chronic diseases are the leading cause of death and disability and account for 60% of all deaths worldwide (WHO 2008), the Department of Chronic Disease and Health Promotion of the World Health Organization (WHO) emphasizes the importance of preventing and managing chronic diseases and their risk factors (WHO 2010). Some health conditions have been found to be risk factors, for example, patients with the metabolic syndrome have an increased risk of developing CVD (Mottillo 2010). Similarly, women with a previous history of gestational diabetes have an increased risk of developing type II diabetes (Bellamy 2009). These risk factors may be targeted in interventions aiming to prevent chronic diseases.

Evidence from epidemiologic, experimental and clinical studies has demonstrated a strong relationship between dietary patterns or nutrient intakes, and prevention and management of chronic diseases including diabetes (Champagne 2009), CVD (Lavie 2009), and obesity (Kennedy 2004). Several authoritative health agencies have recommended the adoption of a healthy diet as the cornerstone in preventing and/or managing chronic diseases such as CVD (Lichtenstein 2006), diabetes (Bantle 2008) and cancer (Kushi 2006). For example, lifestyle interventions including dietary changes were shown to reduce the incidence of diabetes by 58% compared to a control group in individuals at high risk in two large randomized controlled trials (RCTs): the Finnish Diabetes Prevention study (Lindstrom 2003) and the Diabetes Prevention Program (Knowler 2002). In line with this, dietitians and other health professionals provide people with dietary advice designed to improve their nutritional intake (Baldwin 2011).

The concept of 'adherence' recognizes the patient’s right to choose whether or not to follow advice, and implies a patient’s active participation in the treatment regimen (Cohen 2009). For chronic disease management including medication and lifestyle changes, non-adherence rates are estimated to be between 50% and 80% (WHO 2003). Thus, poor adherence can be a serious threat to patients’ health and wellbeing (DiMatteo 2002), and also carries an economic burden (DiMatteo 2004a). Adherence is particularly important in the context of chronic diseases requiring long-term therapy and a number of permanent rather than temporary changes in lifestyle behaviours, such as diet, physical activity and smoking (WHO 2003). The extent to which risk-reduction interventions proved to be as effective in research settings as in individuals' real-life settings depends on the patient’s adherence to treatment advice. In that regard, results from an RCT assessing adherence to and effectiveness of four popular diets (Atkins, Zone, Weight Watchers, and Ornish) revealed that level of adherence to dietary advice, rather than the type of diet, was the key determinant of greater weight loss and CVD risk factor reductions (Dansinger 2005). Whether the number of intervention goals that an individual has to reach influences adherence was also addressed in a secondary analysis of the PREMIER study (Young 2009). In this RCT that tested the effects of two multicomponent lifestyle interventions on blood pressure control, the authors reported that individuals with the most physical activity and dietary behaviour goals to achieve reached the most goals (Young 2009).

Measurement of adherence to prescribed dietary advice typically involves: 1) assessment of what the client eats through self-reported methods (e.g. 24-hour recall, food records, food frequency questionnaires, diet history); and 2) determination of the degree to which the diet approximates the recommended dietary plan (e.g. difference between clients’ recommended macronutrient goals and their self-reported intake). Although sparsely used, more objective measures of adherence to diets also exist (e.g. 24-hour urinary sodium excretion to assess adherence to a low sodium diet (Chung 2008)). However, there is no gold standard for the accurate determination of dietary intake. Self-report of energy intake is a characteristic inherent to nutrition-related topics and is found to be underestimated compared to objective measures such as resting energy expenditure assessed by indirect calorimetry (Asbeck 2002). Underreporting energy intake has been observed more frequently in women versus men, (Johnson 1994), in older versus young (Huang 2005), and in obese versus normal weight individuals (Briefel 1997). Although self-report measures are often regarded as susceptible to bias (e.g. over reliance on memory; report error related to meal composition or portion sizes; daily dietary variability; social desirability) (Kumanyika 2000; Wilson 2005) they are a direct, simple and inexpensive method (DiMatteo 2004b), and are readily available for use in practice. Self-report measures can be improved and validated by using multiple measures of adherence and controlling statistically for bias or by using constructs such as body weight, blood pressure or plasma cholesterol concentrations (Hebert 2001; DiMatteo 2004b).

 

Description of the intervention

Adherence to dietary advice has been shown to vary according to gender (Chung 2006), socio-economic status (Reid 1984) and ethnicity (Natarajan 2009). Moreover, numerous barriers to client adherence in health care have been identified. Among them are complexity of treatment plan, and clients’ knowledge of disease and understanding of the importance of treatment in its control and in preventing adverse outcomes (Makaryus 2005 ;Harmon 2006; Robinson 2008). According to a WHO report, "interventions for removing barriers to adherence must become a central component of efforts to improve population health worldwide" (WHO 2003). Although non-adherence is often attributed to clients who are viewed as "non cooperative", "non compliant" and "unable to follow instructions" (Kapur 2008), it is increasingly recognized that health professionals may help their clients overcome barriers to adherence (Harmon 2006) by improving how they approach their clients' problems, how they provide advice, and how they involve their clients in treatment decision making. Although there is a wide diversity of interventions for enhancing adherence to dietary advice, their underlying aim is to prompt change to facilitate the adoption of recommended dietary behaviours.

 

How the intervention might work

Behaviour change theories have proved useful for explaining health-related behaviours, including dietary behaviours. They attempt to identify the determinants that will contribute to predict the adoption of a specific behaviour, and which should be taken into account when developing a behaviour change intervention, such as a method for providing dietary advice. Several models or theories to predict behaviour change can be used in health-related interventions, such as the Health Belief Model (Rosenstock 1974), the Theory of Planned Behaviour (Ajzen 1991), the Theory of Reasoned Action (Fishbein 1981) and the Social Cognitive Theory (Bandura 1986).  More recently, Michie 2011 proposed a framework, the COM-B system, which includes three principal interrelated components of the determination of a behaviour: 1) the motivation (the direct brain process leading to a behaviour), 2) the capability (the individual’s psychological and physical capacity to engage a behaviour) and 3) the opportunity (the factors that lie outside the individual that make the behaviour possible or not) (Michie 2011).The authors also developed a system for characterizing behaviour change interventions and their components in order to facilitate the identification of the effective behaviour change interventions and the implementation of evidence-based practice in this area. According to this system, behaviour change interventions can be classified as nine intervention functions: education, persuasion, incentivisation, coercion, training, restriction, environmental restructuring, modelling and enablement (Michie 2011). These theories or models focus on different determinants or combinations of determinants of the behaviours which could be helpful for developing interventions for enhancing adherence to dietary advice.  

 

Why it is important to do this review

As greater adherence to dietary advice is a critical component in preventing and managing chronic diseases, research is needed to identify the characteristics of interventions that will result in a better agreement between health professionals’ evidence-based dietary advice, and their clients’ eating patterns. Despite growing recognition that non-adherence to dietary advice is a barrier to getting new nutrition knowledge into practice, previous knowledge syntheses have provided decision makers and knowledge users with little practical guidance on the development of useable interventions for enhancing adherence to dietary advice. Studies have reported on interventions designed to enhance adherence to dietary advice by overcoming barriers to adherence. Although some studies have reported positive effects of interventions to enhance adherence to dietary advice, no systematic review specifically assesses dietary interventions that lead to sustained dietary changes or that refer to a wide array of chronic diseases. Haynes 2008 summarized the results of RCTs of interventions to help clients adhere to prescriptions for medications for medical problems, and excluded interventions targeting dietary advice. Bosch-Capblanch 2007 systematically reviewed the effects of contracts between clients and health professionals for improving clients' adherence to treatment, prevention and health promotion activities. Although this review is relevant to our review, it reported only the effect of contracts (as opposed to other interventions), and was not specific to dietary advice. Several non-Cochrane reviews may overlap with our review, but these are not systematic (Brownell 1995b; Brownell 1995a; Burke 1997; Newell 2000; Fappa 2008) and/or are related to only one health condition and not specifically targeting dietary advice (Burke 1997; Newell 2000; Fappa 2008).

This review will improve the knowledge base for adherence to dietary advice; a topic of immense importance for dietetics practice that will also be relevant to clients, and other health professionals.

 

Objectives

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms

To assess the effects of interventions for enhancing adherence to dietary advice for preventing and managing chronic diseases in adults.

 

Methods

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms
 

Criteria for considering studies for this review

 

Types of studies

Randomized controlled trials (RCTs) including cluster RCTs. Because interventions for enhancing adherence to dietary advice aim to initiate dietary changes, a cross-over design in which each client received all interventions could induce a carry-over effect. Therefore, we excluded studies including a cross-over design.

 

Types of participants

Clients, aged 18 years and over, in real-life settings. We define 'client' as an adult participating in a chronic disease prevention or chronic disease management study involving dietary advice. We included clients who had a diet related-chronic disease (e.g. obesity, cardiovascular disease, renal failure, hypertension) or at least one risk factor for a chronic disease (e.g. overweight, hyperlipidaemia). We included family or non-family caregivers such as wife/husband or individual living with the client and involved in meal planning and preparation. We also included studies involving health professionals delivering dietary advice.

 

Types of interventions

We included studies assessing the effects of a single intervention or multiple interventions involving chronic disease prevention and management, on adherence to dietary advice. 'Intervention' was defined as the method used to facilitate changes in dietary habits through dietary advice. To structure the presentation of results, we grouped interventions according to the intervention functions of the behaviour change wheel developed by Michie and colleagues (Michie 2011). Therefore, we classified interventions to enhance adherence to dietary advice as:

  • Education (increasing knowledge or understanding);
  • Persuasion (using communication to induce positive or negative feelings or stimulate action);
  • Incentivisation (creating expectation of reward);
  • Coercion (creating expectation of punishment or cost);
  • Training (imparting skills);
  • Restriction (using rules to reduce the opportunity to engage in the target behaviour);
  • Environmental restructuring (changing the physical or social context);
  • Modelling (providing an example for people to aspire to or imitate) ;
  • Enablement (increasing means/reducing barriers to increase capability or opportunity);
  • Multiple (combination of two or more different interventions).

We included studies making the following comparisons:

  • Single intervention for enhancing adherence to dietary advice versus no intervention (control) or a reference standard of care (usual care);
  • Single intervention for enhancing adherence to dietary advice versus single or multiple interventions with a similar purpose (to enhance adherence to dietary advice);
  • Multiple interventions for enhancing adherence to dietary advice versus no intervention (control) or a reference standard of care (usual care);
  • Multiple interventions for enhancing adherence to dietary advice versus single or multiple interventions for enhancing adherence to dietary advice.

The term 'reference standard of care' refers to the usual dietary intervention performed to address a specific health condition. For example, in Amato 1990 two approaches were used with patients who were severely obese using the same dietary advice: 1) weight loss advice versus 2) weight loss advice combined with psychotherapy. The approach with weight loss advice was the reference standard of care while the approach with weight loss advice combined with psychotherapy was the intervention for enhancing adherence to dietary advice. Furthermore, only studies comparing interventions with the same dietary advice component (e.g. increase consumption of fruits and vegetables, decrease fat intake) but differing in terms of the method for changing dietary habits through dietary advice (e.g. education (counselling and follow-up with health professional, educational tools)) were included. We excluded studies assessing adherence to dietary advice for which interventions were not a method for facilitating changes in dietary habits through dietary advice (e.g. medication for weight loss, exercise, etc.).

We excluded studies that aimed primarily to evaluate the effects of an experimental diet or a food plan on health outcomes, and for which adherence was monitored as a secondary outcome to justify, for example, the validity of the results, as these interventions were not designed for enhancing adherence to dietary advice. We only included studies including food-based dietary advice and representing real-life conditions. Therefore, we excluded studies involving the provision of meals, food items or dietary supplements (e.g. vitamin, mineral, omega-3 fatty acid).

 

Types of outcome measures

 

Primary outcomes

  • Client adherence to dietary advice (e.g. biochemical measures within acceptable limits, mean dietary intake, proportion of clients achieving the dietary advice). We included studies reporting adherence to dietary advice as a primary outcome, namely those clearly mentioning a measurement of diet adherence in the title or the objective of the study and/or those reporting the proportion of patients adhering to dietary advice. We excluded studies reporting mean dietary intake without specifically assessing adherence to dietary advice.

 

Secondary outcomes

  • Process measures: e.g. attendance at or participation in individual counselling or group sessions, number of completed food records returned to research coordinators, client or family or non-family caregivers’ satisfaction with the dietary or counselling approaches, health professionals’ skills in performing the experimental interventions or their satisfaction with the counselling approach.
  • Client-based health or behaviour outcomes: e.g. blood pressure; plasma cholesterol concentration; plasma glucose concentration; body weight; relief of symptoms; smoking; physical activity; blood glucose monitoring.
  • Organisational outcomes: e.g. cost; time; resources required by client, family or non-family caregivers, or healthcare professionals.
  • Harms or secondary effects: e.g. confusion regarding new eating patterns; feelings of lack of confidence or skills in preparing meals; unhappiness at loss of traditional meals.

 

Search methods for identification of studies

 

Electronic searches

We conducted a systematic search, using 29 September 2010 as the cut-off date, in the following electronic databases:

  • The Cochrane Library, issue 9 2010 (via Wiley);
  • PubMed;
  • EMBASE (Embase.com);
  • CINAHL (Ebsco);
  • PsycINFO (PsycNet).

We present detailed search strategies in Appendix 1; Appendix 2; Appendix 3; Appendix 4; Appendix 5. There were no language restrictions and all databases were searched from their start date.

 

Searching other resources

We conducted additional searches for unpublished studies through grey literature: 

  • Recent years of relevant conference, symposium and colloquium proceedings and abstracts:

    • 2009-10 Scientific sessions of the American Diabetes Association;
    • 2009-10 Scientific sessions of the American Heart Association;
    • 2009-10 Food and Nutrition Conference and Expo of the American Dietetic Association;
    • 2010 Canadian Diabetes Association/Canadian Society of Endocrinology and Metabolism Professional Conference and Annual Meeting;
    • 2009 International Diabetes Federation World Diabetes Congress North America;
    • 2009-10 Dietitians of Canada National Conference;
    • 2009-10 Obesity Society Annual Scientific Meeting;
    • 2009-10 Experimental Biology Meeting;
    • 2009-10 Canadian Nutrition Society;
  • Web-based registries of clinical trials (US National Institutes of Health, The National Library of Medicine, Current Controlled Trials);
  • Bibliographies of included studies;
  • Contact with experts in the field to request details of any other known studies.

 

Data collection and analysis

 

Selection of studies

Two review authors independently assessed the eligibility of papers identified by the search strategy. All titles and abstracts were screened according to pre-established inclusion criteria (see Criteria for considering studies for this review). We retrieved full text copies of papers judged to be potentially relevant to the review. Disagreements were resolved by discussion between the two review authors, and when consensus was not reached, with a third review author. We attempted to contact authors to obtain further details of papers containing insufficient information to make a decision about eligibility. If no response was provided, we sent up to two reminders and, when possible, also contacted one co-author. We contacted 81 authors of whom 67 provided a response.

 

Data extraction and management

Two review authors performed the data extraction independently from all included studies using a modified version of the Cochrane Consumers and Communication Review Group data extraction template (CCCRG 2010). In addition to the standard form derived from the data extraction template of the Cochrane Consumers and Communication Review Group, other relevant information was extracted including:

  • Food-based dietary advice;
  • Rationale underlying the dietary advice (e.g. clinical practice guidelines, other evidence-based sources);
  • Adherence assessment method (proportion of clients achieving the dietary advice, biochemical measures);
  • Description of the intervention (eg. education, persuasion, training).

Any discrepancies in judgement were resolved by discussion and consensus, or with a third review author. Where information was missing, we contacted the corresponding author. If no answer was provided, we sent up to two reminders and, when possible, also contacted one co-author. We contacted 38 authors of included studies, of whom 22 provided a response.

 

Assessment of risk of bias in included studies

Two review authors assessed and reported on the risk of bias of included RCTs in terms of the following individual elements that affect risk of bias:

  • Random sequence generation;      
  • Allocation concealment;
  • Blinding - clients, providers and outcome assessors;
  • Incomplete outcome data;
  • Selective reporting;
  • Other bias. 

Each of the risk of bias items was assessed as 'low risk of bias', 'high risk of bias' and 'unclear risk' based on the study reports and/or additional information provided by the study authors. Any discrepancies in judgement were resolved by discussion and consensus, or with a third review author.

 

Measures of treatment effect

The table Characteristics of included studies includes descriptions of study design, setting, country, chronic disease, type of participants (age, sex, ethnicity), sample size, intervention(s) and/or control/usual care, measurement of diet adherence, dietary advice, drop-out rate and providers. Sample size is presented as the number of randomized clients, or when the authors did not report it, as the number of completers. Drop-out rate is presented as reported or as calculated when the authors did not report it.

Since the included studies addressed a wide range of interventions, measures of diet adherence, dietary advice, nature of chronic diseases, and duration of interventions and follow-up, it was impossible to perform meta-analyses. For this reason, we could not apply all the methods outlined in the protocol (Desroches 2010) but present these in Appendix 6 for application in future updates of the review. To facilitate the presentation of results, two authors independently classified included studies according to the function of the intervention (Michie 2011). Any discrepancies in judgement were resolved by discussion and consensus, or with a third review author. The method(s) for facilitating changes in dietary habits through dietary advice used in the intervention group and differing from the method(s) used in the comparative group (control, usual care or other intervention group) was (were) defined as the intervention and was (were) classified according to different categories of interventions (education, persuasion, incentivisation, coercion, training, restriction, environmental restructuring, modelling, enablement and multiple). Representing each category of interventions, eight additional tables (Additional tables) summarize narratively the number of studies and participants per intervention, the effect on diet adherence and the quality of evidence (GRADE) (Higgins 2011). In case of discrepancies between the results provided by the authors and the risk ratio (RR) or the standardized mean difference (SMD) calculated using Review Manager 5 ('RevMan') software (RevMan 2012), we selected the results provided by RevMan to complete the Additional tables. Some studies assessed and therefore reported multiple diet adherence outcomes (e.g. adherence to fiber intake and adherence to cholesterol-restricted diet) and/or evaluated diet adherence outcome(s) at different times (e.g. one month, three months, six months). Consequently, we used vote counting, that is we reported the number of diet adherence outcomes favouring the intervention out of the total number of diet adherence outcomes reported, regardless of the statistical significance or size of their results (Higgins 2011), to assess studies that reported diet adherence outcomes between an intervention group and a control/usual care group. Studies are described in more than one category of intervention if they investigated more than one intervention (Baraz 2010; Cummings 1981; Hsueh 2007; Jones 1986; Kendall 1987; Logan 2010; Mahler 1999; McCulloch 1983). Only studies that compared an intervention with a control/usual care group were included in these Additional tables.

We used RevMan to create forest plots when diet adherence outcomes provided raw and complete data (means and standard deviations for continuous data, and number of events and number of total observations for dichotomous data). We analyzed dichotomous data by determining the RR and 95% confidence intervals. We analyzed continuous data by determining the SMD of the intervention and the control groups in each study with 95% confidence intervals. Only studies comparing a single or multiple intervention group with a control/usual care group were included in forest plots. We used mean differences between pre-post intervention to calculate SMD. When these data were not known, and that baseline data were available for the two groups, we corrected the standard effect size by calculating the difference between pre- and post-intervention values. The pooled estimates standard deviation was used to calculate the standard deviation of this difference. When no baseline data were reported, groups were considered to be similar before the intervention. Outcomes with data including covariate-adjusted means or imputed means were not analysed with forest plots. For these studies, we presented the qualitative data as reported by the study authors. Some elevated SMDs could represent a high diet adherence (e.g. fruit, vegetable and fiber intakes) whereas some elevated SMDs could represent a low diet adherence (e.g. energy, fat and sodium intakes). Therefore, to correct for difference in the direction of the scale in forest plots, means of the intervention and the control groups were multiplied by -1 for outcomes where elevated SMD represented a high diet adherence (e.g. fruit, vegetable and fiber intakes). When authors did not report statistical analyses, we used data to calculate the SMD or the RR in RevMan in order to compare differences in outcomes between groups.

 

Assessment of heterogeneity

We did not explore heterogeneity due to the wide range of interventions, measures of diet adherence, dietary advice, nature of chronic diseases, and duration of interventions and follow-up addressed in included studies.

 

Consumer participation

The Cochrane Consumers and Communication Review Group's editorial process for the protocol (Desroches 2010) and the review involved two anonymous consumer referees. We also sought additional feedback throughout the review process from representatives of the Dietitians of Canada to ensure that important issues for health professionals were addressed.

 

Results

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms
 

Description of studies

See: Characteristics of included studies; Characteristics of excluded studies; Characteristics of studies awaiting classification; Characteristics of ongoing studies.

 

Results of the search

From the searches, we identified 5183 potentially-relevant publications after duplicates were removed. From these, we excluded 4786 publications after examining the titles and abstracts, and we retrieved 398 full-texts of potentially-relevant publications. From these, 42 publications (describing 38 unique studies) met our inclusion criteria and were considered as eligible. We classified a further 5 publications (describing 6 studies) as ongoing studies (see Characteristics of ongoing studies), and 20 publications as studies awaiting classification (See Characteristics of studies awaiting classification) (see Figure 1, Study Flow Diagram).

 FigureFigure 1. Study flow diagram.

 

Included studies

Three included studies were described in more than one publication. First, Jiang's PhD thesis was published later in an electronic journal (Jiang 2004). Similarly, Chow's PhD thesis was published later in an electronic journal (Wong 2010). Miller 1988, Miller 1989 and Miller 1990 (Miller 1988) all described the same study and reported results for diet adherence at 30 and 60 days, 1 year and 2 years, respectively. We refer to this study as Miller 1988. Therefore we included 38 studies reported in 42 publications (See Characteristics of included studies).

All included studies were RCTs. Only one of them used cluster randomisation (Wood 2008).

 

Location, setting and duration

Studies were conducted in the following countries:


CountryNumber of studiesStudies

United States of America14Aldarondo 1999; Beasley 2008; Becker 1998; Cummings 1981; Gans 1994; Gill 2010; Hsueh 2007; Hyman 2007; Kendall 1987; Mahler 1999; Micco 2007; Miller 1988; Racelis 1998; Scisney-Matlock 2006

United Kingdom7Bennett 1986; French 2008; Grace 1996; Jones 1986; Logan 2010; McCulloch 1983; Morey 2008

China5Chen 2006; Chiu 2010; Jiang 2004; Wong 2010; Zhao 2004

Canada4Arcand 2005; Conrad 2000; Gucciardi 2007; Ryan 2002

Brazil1Assuncao 2010

Iran1Baraz 2010

The Netherlands1Blanson 2009

Finland1Laitinen 1993

Norway1Meland 1994

South Africa1Stewart 2005

Taiwan1Tsay 2003

Multiple (France, Italy, Poland, Spain, Sweden, United Kingdom, Denmark and the Netherlands)1Wood 2008



All included studies were directed towards clients and none of them was directed towards family or non-family caregivers or health professionals.

An outpatient setting was reported in the majority of the included studies (n = 31). Four studies were carried out in a research center setting (Beasley 2008; Blanson 2009; Hsueh 2007; Micco 2007) while one study (Gans 1994) included two settings (workplace and community). In two studies, the setting could not be identified (Aldarondo 1999; Bennett 1986).

Nineteen studies evaluated diet adherence to dietary advice over a period of less than 6 months (Aldarondo 1999; Arcand 2005; Baraz 2010; Beasley 2008; Bennett 1986; Blanson 2009; Chen 2006; Chiu 2010; Cummings 1981; Gans 1994; Gill 2010; Grace 1996; Gucciardi 2007; Jones 1986; Mahler 1999; Meland 1994; Scisney-Matlock 2006; Wong 2010; Zhao 2004), nine studies had a duration between 6 and 12 months (Assuncao 2010; Conrad 2000; Hsueh 2007; Jiang 2004; Kendall 1987; McCulloch 1983; Ryan 2002; Stewart 2005; Tsay 2003), while only 10 studies evaluated diet adherence to dietary advice over a 12-month period or more (Becker 1998; French 2008; Hyman 2007; Laitinen 1993; Logan 2010; Micco 2007; Miller 1988; Morey 2008; Racelis 1998; Wood 2008).

 

Clients

The 38 studies included in this review involved 9445 clients. The range in the number of clients in each study varied from 7 to 5405 (median = 83). Only 13 of the 38 studies provided a power calculation (Aldarondo 1999; Assuncao 2010; Beasley 2008; Chiu 2010; French 2008; Hyman 2007; Jiang 2004; Meland 1994; Stewart 2005; Tsay 2003; Wong 2010; Wood 2008; Zhao 2004) and among them, 10 studies recruited the number of clients according to their power analysis (Aldarondo 1999; Assuncao 2010; Beasley 2008; French 2008; Jiang 2004; Meland 1994; Stewart 2005; Tsay 2003; Wong 2010; Zhao 2004).

 

Prevention of chronic diseases

Five studies included clients receiving dietary advice for the prevention of chronic diseases, such as clients with a high risk of CVD (clients having dyslipidaemia (Gans 1994; Grace 1996), siblings of individuals with coronary heart diseases (Becker 1998)) and overweight clients (Blanson 2009; Jones 1986).

 

Management of chronic diseases

Twenty-seven included studies addressed dietary advice for chronic disease management. Eight studies included clients receiving dietary advice for the management of CVD (heart failure (Arcand 2005), coronary heart disease (Logan 2010; Zhao 2004), coronary artery disease (Conrad 2000; Mahler 1999), peripheral artery disease (Racelis 1998), angina pectoris and myocardial infarction (Jiang 2004; Miller 1988)); six studies involved the management of diabetes (French 2008; Gucciardi 2007; Kendall 1987; Laitinen 1993; McCulloch 1983; Ryan 2002); five studies involved the management of hypertension (Chiu 2010; Hyman 2007; Meland 1994; Scisney-Matlock 2006; Stewart 2005); six studies addressed the management of renal failure (Baraz 2010; Chen 2006; Cummings 1981; Morey 2008; Tsay 2003; Wong 2010); one study addressed the management of obesity (Aldarondo 1999): and one study addressed the management of irritable bowel syndrome (Hsueh 2007).

 

Prevention and management of chronic diseases

Six studies included clients receiving dietary advice for both the prevention and the management of chronic diseases. One study was conducted with clients with coronary heart disease and clients with a high risk of developing CVD (Wood 2008). The remaining five studies included overweight and obese clients (Assuncao 2010; Beasley 2008; Bennett 1986; Gill 2010; Micco 2007).

 

Interventions

Included studies assessed interventions in the following categories:

 
Education

Nine studies offered nutrition counselling and follow-up with a health professional through telephone follow-up (Chiu 2010; Cummings 1981; Racelis 1998; Stewart 2005), group sessions (Gill 2010; Jones 1986) or individual sessions with a dietitian (Jones 1986; Micco 2007) or a nurse (Hsueh 2007). Moreover, four studies used educational tools to provide dietary advice such as video (Baraz 2010; Mahler 1999; McCulloch 1983) or booklet (Kendall 1987).

 
Persuasion

Two studies used reminders (Gans 1994; Ryan 2002).

 
Incentivisation

One study used contracts with rewards (Cummings 1981).

 
Training

Three studies used feedback (Beasley 2008; French 2008; Meland 1994).

 
Restriction

Only one study compared an immediate versus an incremental reduction of fat intake (Conrad 2000).

 
Modelling

Seven studies used nutritional tools such as menus, exchange list and portion size examples in order to enhance diet adherence (Assuncao 2010; Chen 2006; Grace 1996; Kendall 1987; Logan 2010; McCulloch 1983; Scisney-Matlock 2006).

 
Enablement

Three studies used one or more behaviour change techniques, including barrier identification/problem solving (Aldarondo 1999; Bennett 1986; Logan 2010), goal setting (Logan 2010), self-talk (defined as use of self-instruction and self-encouragement to support action by Abraham and Michie (Abraham 2008)) (Aldarondo 1999; Bennett 1986) and teaching to use prompts/cues (defined as teaching the person to identify environmental cues that can be used to remind them to perform a dietary behaviour by Abraham and Michie (Abraham 2008)) (Bennett 1986).

 
Multiple

This category includes 18 studies using a combination of two or more different interventions (Arcand 2005; Baraz 2010; Becker 1998; Blanson 2009; Cummings 1981; Gucciardi 2007; Hsueh 2007; Hyman 2007; Jiang 2004; Jones 1986; Laitinen 1993; Mahler 1999; Miller 1988; Morey 2008; Tsay 2003; Wong 2010; Wood 2008; Zhao 2004).

 

Outcomes

Twenty-eight studies compared two groups (Aldarondo 1999; Arcand 2005; Assuncao 2010; Baraz 2010; Beasley 2008; Becker 1998; Blanson 2009; Chen 2006; Chiu 2010; Conrad 2000; Gill 2010; Grace 1996; Gucciardi 2007; Hsueh 2007; Kendall 1987; Jiang 2004; Laitinen 1993; Logan 2010; Meland 1994; Micco 2007; Miller 1988; Morey 2008; Racelis 1998; Scisney-Matlock 2006; Stewart 2005; Tsay 2003; Wong 2010; Zhao 2004), six studies compared three groups (Bennett 1986; French 2008; Hyman 2007; Mahler 1999; McCulloch 1983; Ryan 2002) and four studies compared four groups (Cummings 1981; Gans 1994; Jones 1986; Wood 2008). Twenty-five studies assessed a single diet adherence outcome (Arcand 2005; Beasley 2008; Becker 1998; Bennett 1986; Blanson 2009; Chen 2006; Chiu 2010; Conrad 2000; Gans 1994; Gill 2010; Gucciardi 2007; Hyman 2007; Jiang 2004; Jones 1986; Logan 2010; Mahler 1999; McCulloch 1983; Meland 1994; Micco 2007; Miller 1988; Morey 2008; Racelis 1998; Scisney-Matlock 2006; Tsay 2003; Zhao 2004) while 13 studies assessed multiple diet adherence outcomes (Aldarondo 1999; Assuncao 2010; Baraz 2010; Cummings 1981; French 2008; Grace 1996; Hsueh 2007; Kendall 1987; Laitinen 1993; Ryan 2002; Stewart 2005; Wong 2010; Wood 2008). Twenty studies assessed diet adherence outcome(s) once (Aldarondo 1999; Arcand 2005; Assuncao 2010; Baraz 2010; Beasley 2008; Becker 1998; Bennett 1986; Blanson 2009; Chen 2006; Chiu 2010; Conrad 2000; French 2008; Gans 1994; Gill 2010; Grace 1996; Gucciardi 2007; Jones 1986; McCulloch 1983; Racelis 1998; Wood 2008), 13 studies assessed diet adherence outcome (s) twice (Cummings 1981; Hsueh 2007; Hyman 2007; Jiang 2004; Kendall 1987; Laitinen 1993; Logan 2010; Mahler 1999; Meland 1994; Micco 2007; Stewart 2005; Wong 2010; Zhao 2004) while 5 studies assessed diet adherence outcome (s) 3 or more times (Miller 1988; Morey 2008; Ryan 2002; Scisney-Matlock 2006; Tsay 2003). Consequently, 32 studies compared diet adherence outcomes between an intervention group and a control/usual care group, and 9 studies compared two intervention groups.

 

Excluded studies

As described in the Characteristics of excluded studies table, reasons for exclusion included: no measure of adherence outcome; not the same dietary advice component in groups; not a randomized controlled trial; provision of meals, food, items or dietary supplements; not involving clients with or at risk of chronic diseases; intervention not intended to improve diet adherence; not a real-life setting; clients were under the age of 18; and study did not involve a nutritional intervention.

 

Risk of bias in included studies

As described in the Characteristics of included studies, eight risk of bias criteria were applied to each study (random sequence generation, allocation concealment, blinding: clients, providers and outcome assessors, incomplete outcome data, selective reporting and other bias). Two studies were rated as low risk on 4 of the 8 criteria (Gucciardi 2007; Zhao 2004), 8 studies were low risk on 3 criteria (Aldarondo 1999; French 2008; Jiang 2004; Meland 1994; Morey 2008; Scisney-Matlock 2006; Stewart 2005; Tsay 2003), 11 studies were rated as low risk on 2 criteria (Arcand 2005; Assuncao 2010; Baraz 2010; Chen 2006; Cummings 1981; Kendall 1987; Laitinen 1993; Logan 2010; Mahler 1999; Ryan 2002; Wong 2010), 11 studies were rated as low risk on one criterion (Beasley 2008; Becker 1998; Bennett 1986; Blanson 2009; Chiu 2010; Conrad 2000; Gill 2010, Hsueh 2007; McCulloch 1983; Miller 1988; Racelis 1998) and six studies were not rated low risk for any criteria (Gans 1994; Grace 1996; Hyman 2007; Jones 1986; Micco 2007; Wood 2008) (see Figure 2).

 FigureFigure 2. Risk of bias summary: review authors' judgements about each risk of bias item for each included study.

 

Allocation

The allocation sequence was adequately generated in the majority of studies (n = 26). Twelve studies did not report sufficient information to determine this risk of bias (Blanson 2009; Conrad 2000; Gans 1994; Grace 1996; Hyman 2007; Jones 1986; McCulloch 1983; Micco 2007; Miller 1988; Racelis 1998; Tsay 2003; Wood 2008).

The allocation was adequately concealed only in seven studies (Assuncao 2010; Jiang 2004; Laitinen 1993; Mahler 1999; Meland 1994; Stewart 2005; Zhao 2004)  while nine studies reported an inadequate allocation (Aldarondo 1999; Baraz 2010; Beasley 2008; Bennett 1986; Cummings 1981; Gucciardi 2007; Kendall 1987; Logan 2010; Miller 1988). The majority of the studies (n = 22) did not describe the allocation concealment in sufficient detail to permit evaluation.

 

Blinding

The majority of the interventions provided to clients were difficult to blind for clients, providers and outcomes assessors. Therefore, only three studies (Aldarondo 1999; Blanson 2009; Scisney-Matlock 2006), two studies (Gucciardi 2007; Tsay 2003) and six studies (French 2008; Gucciardi 2007; Jiang 2004; Kendall 1987; Stewart 2005; Zhao 2004) respectively blinded clients, providers and outcome assessors.

 

Incomplete outcome data

Twelve studies adequately addressed incomplete outcome data (Aldarondo 1999; Arcand 2005; Baraz 2010; Chen 2006; Conrad 2000; McCulloch 1983; Meland 1994; Morey 2008; Racelis 1998; Ryan 2002; Tsay 2003; Zhao 2004) whereas 17 studies did not (Assuncao 2010; Beasley 2008; Becker 1998; Bennett 1986; Blanson 2009; Cummings 1981; Gucciardi 2007; Hyman 2007; Jiang 2004; Jones 1986; Kendall 1987; Laitinen 1993; Logan 2010; Miller 1988; Stewart 2005; Wong 2010; Wood 2008). The principal reason for the incomplete outcome data bias was that missing outcomes are enough to induce clinically-relevant bias in the observed effect estimate. Nine studies reported insufficient information to permit an evaluation of this criterion (Chiu 2010; French 2008; Gans 1994; Gill 2010, Grace 1996; Hsueh 2007; Mahler 1999; Micco 2007; Scisney-Matlock 2006).

 

Selective reporting

Study protocols were available for only one study and all of the study's pre-specified outcomes that were of interest in the study were reported in the pre-specified way. Therefore, only this study (French 2008) was free of suggestion of selective outcome reporting. Eighteen studies incompletely reported some outcomes of interest (Aldarondo 1999; Assuncao 2010; Becker 1998; Conrad 2000; Grace 1996; Hyman 2007; Jiang 2004; Kendall 1987; Laitinen 1993; Meland 1994; Micco 2007; Miller 1988; Morey 2008; Racelis 1998; Ryan 2002; Stewart 2005; Wong 2010; Wood 2008) whereas others provided insufficient information to address this criterion (n = 19).

 

Other potential sources of bias

Eight studies (Cummings 1981; Gucciardi 2007; Logan 2010; Miller 1988; Morey 2008; Scisney-Matlock 2006; Tsay 2003; Wong 2010) appeared free of other potential sources of bias, whereas 13 studies had at least one important risk of bias such as a baseline imbalance between groups which was not taken into consideration in statistical analyses, a diet adherence not clearly defined, a diet adherence assessed by a non-validated self-reporting method, a potential conflict of interest or a potential intervener effect (Assuncao 2010; Beasley 2008; Becker 1998; Chiu 2010; Conrad 2000; French 2008; Gans 1994; Grace 1996; Hsueh 2007; Hyman 2007; Ryan 2002; Stewart 2005; Zhao 2004). Other studies did not report sufficient information to assess other potential sources of bias (n = 17).

 

Effects of interventions

Included studies differed widely according to interventions provided, measures of diet adherence, dietary advice, nature of the chronic diseases and duration of interventions and follow-up. Therefore, data were not pooled statistically. Instead, we present a qualitative analysis described in a narrative table using vote counting for each category of interventions (see Additional tables). We also created forest plots for outcomes from studies comparing a single or multiple intervention group with a control/usual care group (see Figure 3; Figure 4; Figure 5). Among the 32 studies that measured diet adherence outcomes between an intervention group and a control/usual care group, 32 out of 123 diet adherence outcomes favoured the intervention group, 4 favoured the control group whereas 62 had no significant difference between groups. This result was impossible to assess for 25 diet adherence outcomes as data and/or statistical analyses needed for comparison between groups were not provided (Additional tables).

 FigureFigure 3. Forest plot of comparison: 6 Nutritional tools versus control in diet adherence, outcome: 6.1 Continuous data. *Means represent the difference between pre-and post- intervention.
 FigureFigure 4. Forest plot of comparison: 8 Multiple interventions versus control in diet adherence, outcome: 8.1 Continuous data. *Means represent the difference between pre-and post- intervention.
 FigureFigure 5. Forest plot of comparison: 8 Multiple interventions versus control in diet adherence, outcome: 8.2 Dichotomous data. *Means represent the difference between pre-and post- intervention.

 

Education

See  Table 1.

 

Counselling and follow-up with health professional

 
Telephone follow-up

Chiu 2010 assessed the effects of telephone follow-up on: adherence to a sodium-restricted diet; fat intake and fruit and vegetable intake, in clients with hypertension. The authors reported no differences in diet adherence between the intervention group and the control group at eight weeks. However, a greater decrease in systolic and diastolic blood pressure was observed in the intervention group compared to the control group as well as a greater increase in exercise adherence. 

One study (Cummings 1981) reported significantly higher adherence to a potassium-restricted diet and fluid-restricted diet at six weeks in clients with renal failure who received telephone follow-up, compared to clients in the control group. However, these differences were no longer significant at three months. This study also compared clients with renal failure receiving telephone follow-up with clients writing a formal agreement (contract) and with clients writing a contract with the involvement of a family member or friend, but found no differences in adherence to a potassium- and fluid-restricted diet at three months between groups.

Racelis 1998 assessed the effects of telephone follow-up on adherence to diet in clients with peripheral artery disease. The authors indicated that no significant difference was noted between the intervention and the control groups.

Stewart 2005 also evaluated the effects of telephone follow-up on adherence to a sodium-restricted diet in clients with hypertension. The authors reported that a higher proportion of clients adhered to the sodium-restricted diet at 24 weeks in the intervention group compared to the control group, but the difference was no longer significant at 36 weeks. No differences were found in systolic and diastolic blood pressure between groups. The authors also noted no difference in non-adherence to alcohol intake at 24 and 36 weeks between groups.

Among studies using a control/usual care group, three out of ten diet adherence outcomes favoured the intervention group compared to control group and seven diet adherence outcomes had no significant difference between groups (see  Table 1). However, these three diet adherence outcomes favouring the intervention group were no longer significant at a later time point.

 
Group sessions

Gill 2010 evaluated the effects of group sessions in overweight-obese college women on adherence to the Dietary Approaches to Stop Hypertension (DASH) diet. However, the authors did not report measures of diet adherence for the intervention and the control groups, making comparison between groups impossible.

Jones 1986 compared an intervention using group sessions (GS) with three other groups for overweight clients: group sessions with a dietitian combined with a leaflet providing advice to reduce exposure to food cues (GS + cues); individual sessions with a dietitian (IS); individual sessions with a dietitian combined with a leaflet providing advice to reduce exposure to food cues (IS + cues). Adherence to diet at 16 weeks was assessed but no significant difference between groups was found. The SMD for weight loss was calculated using RevMan software (RevMan 2012) and no significant difference was found between groups at 16 weeks (vs 1  SMD -0.24 (95% CI -1.22 to 0.75); vs 2 SMD -0.03 (95% CI - 0.94 to 0.88); vs 3 SMD -0.55 (95% CI -1.55 to 0.46).

Overall, these studies did not allow us to draw conclusions on the effect of group sessions on diet adherence outcomes (see  Table 1).

 
Individual sessions with a dietitian

To assess the effects of a 16-week intervention promoting individual sessions with a dietitian (IS), Jones 1986 compared this intervention in overweight clients with three others: group sessions with a dietitian (GS); 2) group sessions with a dietitian combined with a leaflet providing advice to reduce exposure to food cues (GS + cues); 3) individual sessions with a dietitian combined with a leaflet providing advice to reduce exposure to food cues (IS + cues). Adherence to diet at 16 weeks was assessed but no significant difference was found between groups. The SMD for weight loss was calculated using RevMan 2012 and no significant difference between groups was found at 16 weeks (vs 1  SMD 0.23 (95% CI -0.46 to 0.93); vs 2 = SMD 0.30 (95% CI-0.69 to 1.08); vs 3 SMD 0.59 (95% CI -0.35 to 1.52).

Another study (Micco 2007) evaluated the effects of individual sessions with a dietitian in overweight-obese clients on diet adherence. The authors assessed diet adherence but they did not report measures for the intervention and the control groups, making the comparison between groups impossible. The authors reported no weight loss difference between groups at 12 months.

Overall, these studies did not allow us to draw conclusions on the effect of individual sessions with a dietitian on diet adherence outcomes (see  Table 1).

 
Individual sessions with a nurse

Hsueh 2007 compared a single intervention comprising individual sessions with a nurse, on adherence to dietary advice to increase fiber, vegetable and fruit intakes in clients with irritable bowel syndrome, with a multiple intervention comprised of individual sessions with a nurse alternating with telephone follow-up. The authors reported no difference in the proportion of high-compliant clients for fiber, vegetable and fruit intakes between groups at three months and six months. 

 

Educational tools

 
Video

One study (Baraz 2010) compared a single intervention using a video as an educational tool with a multiple intervention using a booklet as educational tool, combined with group sessions in clients with chronic end-stage renal disease. The authors did not report the proportion of clients classified as adherent to diet for both groups, making a comparison between groups impossible. The risk ratio (RR) for the proportion of clients who adhered to the diet and fluid-restricted diet was calculated using RevMan and no difference was found between groups at two months for diet (RR 0.48 (95% CI 0.17 to 1.35)) and fluid-restricted diet (RR 0.81 (95% CI 0.25 to 2.57)).

Mahler 1999 evaluated the effects of a video as an educational tool on adherence to a cholesterol and saturated fat-restricted diet in clients with coronary artery disease. Adherence to a cholesterol and saturated fat-restricted diet was significantly higher in the intervention group compared to the control group at one month but this difference was no longer significant at three months. The authors also compared the intervention with another intervention using a video as an educational tool combined with relapse prevention/coping planning, and found no difference between groups.

Another study (McCulloch 1983) reported a significant difference in day-to-day consistency in carbohydrate intake in clients with insulin dependent diabetes receiving an intervention using a video as an educational tool, compared to the usual care group at six months. Moreover, glycated haemoglobin (HbA1c) was significantly lower in the intervention group than in the usual care group at six months. The authors also compared the intervention with another intervention using nutritional tool and no difference between groups was noted.

Among studies using a control/usual care group, two out of three diet adherence outcomes favoured the intervention group compared to the control/usual care group and one diet adherence outcome had no significant difference between groups (see  Table 1). However, one out of two diet adherence outcomes favouring the intervention group was no longer significant at a later time point.

 
Booklet

Kendall 1987 compared an intervention using a booklet as an educational tool with an intervention using exchange lists as a nutritional tool in clients with non-insulin-dependent diabetes. No difference between groups was reported for adherence to energy, protein, vitamin A, vitamin C, thiamine, riboflavin, niacin, calcium, phosphorus, iron and zinc intakes at three and six months. Moreover, there was no difference between groups for health outcomes such as systolic and diastolic blood pressure, weight, plasma glucose, HbA1c, serum cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol and serum triglycerides at six months.

 

Persuasion

See  Table 2.

 
Reminders

Gans 1994 compared three interventions using reminders with a usual care group in clients with elevated blood cholesterol: 1) clients received the reminder, 2) physicians received a reminder postcard which they could mail to the clients, 3) clients received the reminder in addition to the physicians who received a reminder postcard which they could mail to the clients. The authors reported no difference in the proportion of clients that adhered to diet in any of these groups compared to the usual care group at three months, and no difference between groups for the compliance to lifestyle recommendations at three months.

Another study (Ryan 2002) compared two interventions using knowledge and self-care practices as reminders with a control group in clients with type II diabetes: 1) reminders provided to clients at two weeks, three months and six months, 2) reminders provided to clients at three months and six months. The authors reported adherence to frequency of meals and snacks combined for all three groups, making comparison between groups impossible.

Overall, the studies used reminders for patients and physicians (Gans 1994) or for patients (Ryan 2002) to enhance adherence to dietary advice. Among studies using a control/usual care group, three out of 19 diet adherence outcomes had no significant difference between groups. It was impossible to assess this result for 16 diet adherence outcomes since data and/or statistical analyses needed for comparison between groups were not provided (see  Table 2).

 

Incentivisation

See  Table 3.

 
Contracts with rewards

One study (Cummings 1981) reported significantly higher adherence to a potassium-restricted diet and to a fluid-restricted diet at six weeks in clients with renal failure who wrote a behavioural contract, compared to clients in the control group (see  Table 3). However, these differences were no longer significant at three months (see  Table 3). This study also compared clients with renal failure writing a contract with clients receiving telephone follow-up and with clients writing a contract with the involvement of a family member or friend but no difference was noted in adherence to the potassium-restricted diet and fluid-restricted diet at six weeks and three months between groups.

 

Training

See  Table 4.

 
Feedback

Beasley 2008 reported a higher adherence to energy, fat, saturated fat and cholesterol intakes in overweight-obese clients in the intervention group using feedback based on self-monitoring using an electronic food diary compared to the control group. However, no difference in weight loss was observed between groups.

French 2008 compared two interventions using feedback based on self-monitoring of blood glucose with a usual care group in clients with type II diabetes: 1) less intensive intervention, 2) most intensive intervention. Adherence to general and specific diet at 12 months was greater in the control group compared to both intervention groups.

Another study (Meland 1994) assessed the effects of feedback using self-monitoring of urine chloride concentration on adherence to a sodium-restricted diet in clients with hypertension. No difference was reported in adherence to the sodium-restricted diet or in blood pressure between the intervention group and the control group at one and three months.

In this category, three studies used feedback based on self-monitoring using an electronic food diary (Beasley 2008), blood glucose (French 2008) and urine chloride concentration (Meland 1994). Among studies using a control/usual care group, one out of seven diet adherence outcomes favoured the intervention group compared to the control/usual care group, four favoured the control group whereas two had no significant difference between groups (see  Table 4).

 

Restriction

See  Table 5.

Conrad 2000 assessed the effects of an intervention proposing an incremental reduction in fat to a goal of 10% of energy intake compared to an intervention proposing an immediate reduction in fat to a goal of 10% of energy intake in clients with coronary artery disease. The authors did not compare adherence to fat intake advice between groups. Therefore, we calculated the SMD for adherence to the very low fat diet using RevMan 2012 and found no differences between groups at seven months (SMD -1.88 (95% CI -4.00 to 0.23)) (see also  Table 5).

 

Modelling

See  Table 6.

 
Nutritional tools

Assuncao 2010 assessed the effects of nutritional tools such as portion size examples and food lists on diet adherence in overweight-obese clients using an intention-to-treat analysis. Authors reported a significant enhancement of adherence to sodium and sweet food intake goals at six months in clients in the intervention group compared with those receiving usual care. However, a discrepancy was found between the results provided by the authors and the SMD calculated using RevMan which showed no difference for adherence to sweet food intake at six months between groups. No difference was found between groups for adherence to recommended energy, protein, fat, carbohydrate, cholesterol, fiber, fruit and vegetable intakes (see  Analysis 1.1). An increase in physical leisure activity as well as a decrease in fasting glucose were reported in the intervention compared to the usual care group at six months, whereas no difference between groups was observed for weight loss, blood pressure and lipid profile.

Chen 2006 reported a higher proportion of intervention-group clients with renal failure reaching the target for protein intake at one month using menu suggestions, exchange lists and portion sizes as nutritional tools compared to the control group.

Grace 1996 evaluated the effects of nutritional tools such as an additional package containing low-fat cooking methods and low-fat recipe adaptation on adherence to energy and fat intakes in clients with hyperlipidaemia. The authors reported a higher reduction in percentage of fat intake in the intervention group compared to the control group. However, they reported no difference for energy change between the intervention and the control groups at 12 weeks (see also  Analysis 1.1).

Kendall 1987 compared an intervention using exchange lists as a nutritional tool with an intervention using a booklet as an educational tool in clients with non-insulin-dependent diabetes. No difference between groups was reported for adherence to energy, protein, vitamin A, vitamin C, thiamine, riboflavin, niacin, calcium, phosphorus, iron and zinc intakes at three and six months. Moreover, there was no difference between groups for health outcomes such as systolic and diastolic blood pressure, weight, plasma glucose, HbA1c, serum cholesterol, LDL-cholesterol, HDL-cholesterol and serum triglycerides at six months.

One study (Logan 2010) compared an intervention using recipes and meal plans with an intervention using barrier identification/problem solving and goal setting in clients with coronary heart disease. The authors reported no difference between groups for adherence to the Mediterranean diet at 6 and 12 months.

Another study (McCulloch 1983) reported no difference in day-to-day consistency in carbohydrate intake in clients with insulin-dependent diabetes following an intervention using exchange lists and lunch time with health professionals as nutritional tools, compared to usual care group. However, HbA1c was significantly lower in the intervention group at 9 months compared to the control group. The authors also compared the intervention with another intervention using a video as an educational tool and found no difference between groups.

Scisney-Matlock 2006 evaluated the effects of wheels and bar charts displaying Cognitive Representations of the DASH diet as a nutritional tool on adherence to the DASH diet in clients with hypertension compared to a control group. The authors reported results grouped for both groups, making comparison between groups impossible.

To summarize the interventions in this category: two studies included portion sizes (Assuncao 2010; Chen 2006), three studies used menu suggestions and recipes (Chen 2006; Grace 1996; Logan 2010), three studies included exchange lists (Chen 2006; Kendall 1987; McCulloch 1983), one study used an additional package containing low-fat cooking methods (Grace 1996), one study used lunch time with health professionals (McCulloch 1983), and one study used wheels and bar charts displaying Cognitive Representations of the DASH diet (Scisney-Matlock 2006) as nutritional tools in their intervention.

Among studies using a control/usual care group, 3 out of 17 diet adherence outcomes favoured the intervention group and 11 diet adherence outcomes had no significant difference between groups. It was impossible to assess this result for three diet adherence outcomes as data and/or statistical analyses needed for comparison between groups were not provided ( Table 6).

 

Enablement

See  Table 7.

 
Behaviour change techniques

Aldarondo 1999 reported no difference in adherence to energy, fat and saturated fat intake at 14 weeks between the intervention group using barrier identification/problem solving and self-talk compared to the control group in obese clients.

Another study (Bennett 1986) compared three interventions using behavioural change techniques in overweight-obese clients: 1) teaching clients to use prompts/cues, 2) self-talk, 3) barrier identification/problem solving. The authors reported that clients in the intervention group using food cues adhered more closely to energy intake goals than those in the two other groups between baseline and 15 weeks.

One study (Logan 2010) compared an intervention using barrier identification/problem solving and goal setting with an intervention using recipes and meal plans as nutritional tools in clients with coronary heart disease. The authors reported no difference between groups for adherence to the Mediterranean diet at 6 and 12 months.

Overall, in this category: three studies used behavioural change techniques such as barrier identification/problem solving and self-talk (Aldarondo 1999), teaching clients to use prompts/cues, self-talk and barrier identification/problem solving (Bennett 1986) and barrier identification/problem solving and goal setting (Logan 2010).

Only one study used a control group and three out of three diet adherence outcomes had no difference between groups (see  Table 7).

 

Multiple interventions

See  Table 8.

Arcand 2005 evaluated the effects of individual sessions with a dietitian combined with goal setting, on adherence to a sodium-restricted diet in clients with heart failure. The authors did not compare adherence to the sodium-restricted diet nor blood pressure between groups. Therefore, we calculated the SMD for adherence to the sodium-restricted diet and blood pressure using RevMan, and found no difference between groups for sodium-restricted diet (see also  Analysis 2.1), systolic blood pressure (SMD-0.30 (95% CI -0.88 to 0.27)) and diastolic blood pressure (SMD-0.53 (95% CI -1.11 to 0.05)).

One study (Baraz 2010) compared a multiple intervention using a booklet as educational tool combined with group sessions, with a single intervention using a video as an educational tool, in clients with chronic end-stage renal disease. The authors did not report the proportion of clients classified as adherent to diet for both groups, making comparison between groups impossible. Therefore, we calculated the RR for the proportion of clients who adhered to the diet and fluid-restricted diet at two months, using RevMan, and found no difference between groups.

Using an intention-to-treat analysis, Becker 1998 reported no difference in the proportion of clients at risk of coronary heart disease who received telephone follow-up combined with a barrier identification/problem solving intervention for adherence to a fat-restricted diet at two years, compared to clients in the usual care group. Moreover, no difference was found for LDL-cholesterol, HDL-cholesterol and triglyceride levels at two years between groups.

Blanson 2009 evaluated the effects of self-monitoring using a computer assistant combined with feedback using motivational interviewing in overweight clients. They reported no significant difference in adherence to diet at 28 days between the intervention and the control groups.

Cummings 1981 reported a significantly higher adherence to a fluid-restricted diet at six weeks in clients with renal failure asked to write a formal agreement (contract) with the involvement of a family member or friend, compared to clients in the control group. However, these differences were no longer significant at three months. This study also compared clients writing a formal agreement (contract) with the involvement of a family member or friend, with clients writing a contract, and with clients who received telephone follow-up, but no differences in adherence to a potassium- and fluid-restricted diet at three months were found between groups.

In type II diabetes clients, the comparison of an intervention using group sessions and nutritional tools combined with barrier identification/problem solving versus control (Gucciardi 2007) showed a higher adherence to dietary advice in the intervention group at three months. However, the authors reported no difference in HbA1c between the groups at three months (see also  Analysis 2.1).

Hsueh 2007 compared a multiple intervention comprising individual sessions with a nurse alternating with telephone follow-up on adherence to fiber, vegetable and fruit intakes in clients with irritable bowel syndrome, with a single intervention comprising individual sessions with a nurse. The authors reported no difference in the proportion of high-compliant clients for fiber, vegetable and fruit intakes between groups at three and six months.  

To assess the effectiveness of an intervention using telephone follow-up combined with motivational interviewing, Hyman 2007 compared two interventions in clients with hypertension with a usual care group: 1) simultaneous behaviour change (stop smoking, reduce dietary sodium level and increase physical activity); 2) sequential behaviour change (stop smoking, then reduce dietary sodium levels and finally increase physical activity). A higher proportion of clients adhered to the sodium-restricted diet in the simultaneous group, compared to the sequential intervention and the usual care group at six months, but no difference was observed at 18 months. No difference was reported for blood pressure between groups (see also  Analysis 2.2).

Jiang 2004 assessed the effects of an intervention using individual sessions with a nurse and telephone follow-up combined with goal setting, on adherence to the Adult Treatment Panel (ATP) step II diet (hypocholesteraemic diet) in clients with angina pectoris or myocardial infarction. Using an intention-to-treat analysis, the authors reported better adherence to the step II diet in the intervention group compared to the usual care group at three and six months. At three months, triglyceride, total cholesterol, LDL-cholesterol levels and blood pressure decreased significantly more in the intervention group than the usual care group, while no difference was noted for HDL-cholesterol and body weight. At six months, only the differences in triglyceride, total cholesterol and LDL-cholesterol levels remained significant.

Jones 1986 compared four interventions in overweight clients: group sessions with a dietitian (GS); group sessions with a dietitian combined with a leaflet providing advice to reduce exposure to food cues (GS + cues); individual sessions with a dietitian (IS); individual sessions with a dietitian combined with a leaflet providing advice to reduce exposure to food cues (IS + cues). The authors found no significant difference between groups for adherence to diet, as well as for weight loss, at 16 weeks.

Laitinen 1993 evaluated the effects of individual sessions with a dietitian and nutritional tools combined with goal setting, on adherence to total fat, saturated fat, unsaturated fat, carbohydrate, fiber and cholesterol advice in clients with non-insulin-dependent diabetes. Although the authors reported no differences for total, saturated and unsaturated fat intake at three months, there was a higher proportion of clients who adhered to total and saturated fat intake recommendations in the intervention group compared to the usual care group at 15 months, whereas a higher proportion of clients adhered to unsaturated fat in the usual care group at 15 months. However, a discrepancy was found between the results provided by the authors and the RR calculated using RevMan which revealed no difference for adherence in total fat and unsaturated fat at 15 months between groups. Fasting blood glucose and HbA1c decreased significantly more in the intervention group at 15 months than in the control group, while no difference was noted for body weight, total cholesterol and HDL-cholesterol levels. From data provided by the authors, we used RevMan to calculate the SMD for the proportion of clients who adhered to carbohydrate, fiber and cholesterol intakes, and found no differences between groups at 3 and 15 months (see also  Analysis 2.2).

Mahler 1999 assessed the effects of a video as educational tool combined with relapse prevention/coping planning on adherence to a cholesterol- and saturated fat-restricted diet in clients with coronary artery disease. Adherence to a cholesterol- and saturated fat-restricted diet was significantly higher in the intervention group compared to the control group at one month, but this difference was no longer significant at three months. The authors also compared the intervention with another intervention using a video as an educational tool, and found no difference between groups.

Miller 1988 evaluated the effects of individual sessions with a dietitian combined with barrier identification/problem solving and goal setting in clients with myocardial infarction. While no difference was found at 30 days, 60 days and 1 year, the authors reported a significant difference in adherence to diet at 2 years between the intervention and the control groups.

Morey 2008 compared an intervention including individual sessions with a nurse, a booklet as educational tool and reminders combined with motivational interviewing intervention with a control group. They reported a higher proportion of clients with end-stage kidney disease adhering to a phosphate-restricted diet at three months in the intervention group compared to the control group. Data for adherence to the phosphate-restricted diet at 6 and 12 months were not reported (see also  Analysis 2.2).

A multiple intervention (Tsay 2003) including self-monitoring in a diary and feedback combined with stress management and goal setting in clients with end-stage renal disease showed a significant group main effect in adherence to a fluid-restricted diet when baseline mean weight gains were applied as covariate. From data provided by the authors, we used RevMan to calculate the SMD for adherence to a fluid-restricted diet at 1 month, 3 months and 6 months, respectively. No difference was found between groups at one month but adherence to a fluid-restricted diet at three months and six months was significantly higher in the intervention group compared to the control group (see also  Analysis 2.1).

Wong 2010 reported a difference in the degree of non-adherence to diet at seven weeks in clients with renal failure who received telephone follow-up combined with goal setting compared to clients in the control group. However, a discrepancy was found between the results provided by the authors and the SMD calculated using RevMan which revealed no difference for the degree of non-adherence to diet at seven weeks between groups. No difference was found between groups for the degree of non-adherence to diet at 13 weeks and for the number of days of non-adherence to diet, as well as non-adherence to fluid restriction (degree and days) at 7 and 13 weeks (see also  Analysis 2.1).

Wood 2008 studied two populations: clients with coronary heart disease and clients at high risk of the disease. In clients with coronary heart disease, the authors reported a higher proportion of clients achieving the target for saturated fat, oily fish and fruit and vegetable intakes at one year in the intervention group (individual sessions with a nurse combined with motivational interviewing) compared to the usual care group. No difference was observed in adherence to fish consumption advice between groups. However, a discrepancy was found between the results provided by the authors and the RR calculated using RevMan which revealed a higher proportion of clients achieving the target for fish intake in the intervention group. A higher proportion of clients achieved the target for blood pressure in the intervention group compared to the usual care group, while no difference was found for body weight, and total and LDL-cholesterol levels. In clients at high risk of coronary heart disease, a higher proportion of clients achieving the target of fruit and vegetable intakes was reported at one year in the intervention group, while no difference was observed in adherence to recommended fish and oily fish intakes between groups. However, a discrepancy was found between the results provided by the authors and the RR calculated using RevMan which revealed a higher proportion of clients achieving the target for oily fish and fish intake in the intervention group. A higher proportion of clients also achieved the target for blood pressure and body weight in the intervention group compared to the usual care group while no difference was found for total and LDL-cholesterol levels (see also  Analysis 2.2).

One study (Zhao 2004) evaluating the effects of telephone follow-up as well as individual sessions with a dietitian combined with goal setting in clients with coronary heart disease reported a higher proportion of clients with high adherence to diet in the intervention group compared to the usual care group at 4 and 12 weeks (see also  Analysis 2.2).

Overall, in this category, 13 studies combined an educational intervention with another intervention such as an enablement intervention (Arcand 2005; Becker 1998; Gucciardi 2007; Hyman 2007; Jones 1986, Mahler 1999; Miller 1988; Wong 2010; Wood 2008; Zhao 2004), modelling and enablement interventions (Laitinen 1993), persuasion and enablement interventions (Morey 2008), and two educational interventions with enablement interventions (Jiang 2004). Two studies combined two different educational interventions (Baraz 2010; Hsueh 2007). One study combined a training intervention with an enablement intervention (Blanson 2009) and one study combined two enablement interventions and a training intervention (Tsay 2003). One study combined an incentivisation with a persuasion intervention (Cummings 1981).

In this category, among studies using a control/usual care group, 21 out of 56 diet adherence outcomes favoured the intervention group whereas 32 diet adherence outcomes had no significant difference between groups. It was impossible to assess this result for three diet adherence outcomes as data and/or statistical analyses needed for comparison between groups were not provided ( Table 8). However, 4 out of 21 diet adherence outcomes favouring the intervention group was no longer significant at a later time point.

 

Discussion

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms
 

Summary of main results

This review included 38 studies investigating the effects of interventions enhancing adherence to dietary advice for preventing and managing chronic diseases in adults. Studies reporting at least one diet adherence outcome showing statistically significant differences favouring the intervention group included the following interventions: telephone follow-up, video, contract, feedback, nutritional tools and multiple interventions. However, these interventions also showed no difference in some diet adherence outcomes compared to a control/usual care group. Moreover, the included studies differed widely according to interventions provided, measures of diet adherence, dietary advice, nature of the chronic diseases and duration of interventions and follow-up.

The majority of these studies were conducted in United States of America. Cardiovascular disease, diabetes, hypertension, and renal diseases were the most frequently studied chronic diseases. The adoption of a healthy diet is recommended as a prevention or management strategy for each of these chronic diseases (Lichtenstein 2006; Bantle 2008; Kopple 2001). Interestingly, all studies including clients with renal diseases reported at least one diet adherence outcome showing a statistically significant difference favouring the intervention group, no matter which intervention was provided.

Only 10 of the 38 included studies evaluated diet adherence to dietary advice over a 12-month period (Becker 1998; French 2008; Hyman 2007; Laitinen 1993; Logan 2010; Micco 2007; Miller 1988; Morey 2008; Racelis 1998; Wood 2008). Among those 10 studies, only three studies showed at least one statistically significant difference in diet adherence outcomes favouring the intervention group over a 12-month period.

A broad range of interventions, all related to the method for changing dietary habits through dietary advice, was covered in this review, including education (telephone follow-up, group sessions, individual sessions with a dietitian or a nurse, and educational tools (video or booklet)), persuasion (reminders), incentivisation (contracts with rewards), training (feedback), restriction, modelling (nutritional tools) and enablement (behaviour change techniques). However, the majority of studies included a combination of two or more different interventions.

This review included studies comparing one or more intervention group(s) with one control/usual care group, but also studies comparing two or more intervention groups to each other. However, only comparisons made between an intervention group and a control/usual care group allowed the evaluation of the effect of the intervention alone on adherence to dietary advice. Therefore, among studies that measured diet adherence outcomes between an intervention group and a control/usual care group, 32 out of 123 diet adherence outcomes favoured the intervention group. More specifically, studies reporting at least one diet adherence outcome showing statistically significant differences favouring the intervention group included the following interventions: telephone follow-up (3 out of 10 diet adherence outcomes), video (2 out of 3 diet adherence outcomes), contract (2 out of 4 diet adherence outcomes), feedback (1 out of 7 diet adherence outcomes), nutritional tools (3 out of 17 diet adherence outcomes) and multiple interventions (21 out of 56 diet adherence outcomes). Studies investigating interventions such as a group session, individual session, reminders, restriction and behaviour change techniques reported no diet adherence outcome showing a statistically significant difference favouring the intervention group. However, these results should be interpreted with caution as several studies evaluated two or more diet adherence outcomes. Among those, most of the studies showing a statistically significant difference favouring the intervention group for diet adherence outcome(s) also showed no significant differences between groups for other diet adherence outcome(s) (Assuncao 2010; Cummings 1981; Grace 1996; Hyman 2007; Laitinen 1993; Mahler 1999; McCulloch 1983; Miller 1988; Stewart 2005; Tsay 2003). For example, Laitinen 1993 assessed the effects of a multiple intervention and reported better adherence to saturated fat intake at 15 months in the intervention group whereas no differences were observed for adherence to intake of total, saturated or unsaturated fat carbohydrate, fiber or cholesterol between the intervention group and the control group at either 3 or 15 months. In addition, where studies measured outcomes at multiple time points, the majority of studies reporting a diet adherence outcome favouring the intervention group compared to the control/usual care group in the short-term also reported no significant effect at later time points. Interestingly, the majority of studies involving multiple interventions reported positive results on adherence to dietary advice. However, because multiple components within these interventions acted as co-interventions, it may have introduced confounding effects. Therefore, drawing conclusions about whether the interventions enhanced adherence to dietary advice is very difficult.

 

Overall completeness and applicability of evidence

Although we included a substantial number of studies covering a broad range of chronic diseases and interventions, very few studies assessing a specific chronic disease condition evaluated the same intervention. In addition, measures of adherence and dietary advice varied widely across studies.

This review assessed the effects on adherence related to the intervention alone since only the intervention, related to the method for facilitating changes in dietary habits through dietary advice, differed between the intervention group and the control/usual care group. Comparisons between two or more intervention groups were also reported. However, comparisons between multiple interventions were all different. In order to isolate the effects of the intervention, both clients in the intervention group and the control/usual care group received the same dietary advice related to their chronic disease condition. This situation could explain why adherence to dietary advice in the control/usual care group increased in some studies. However, factors other than the intervention provided could have affected adherence to dietary advice. For example, clients' intrinsic characteristics such as an elevated level of self-efficacy (Mishali 2011; Aljasem 2001) as well as few perceived barriers (Walsh 2011) are associated with better dietary adherence in clients with chronic diseases. Some studies also reported that the client’s stage of change based on the Transtheoretical Model predicted long-term changes in dietary behaviours (Mochari 2010; Blissmer 2010). Therefore, confounding factors should be taken into consideration in studies evaluating adherence to dietary advice.

In this review, secondary outcomes related directly to the chronic disease condition (e.g. HbA1c and/or blood glucose in clients with diabetes, weight for clients with obesity) were reported. Few studies reported other secondary outcomes such as process measures, services outcomes and harms or secondary effects, making interpretation about these secondary outcomes impossible. Fourteen studies comparing an intervention group with a control/usual care group also reported clinical and/or biochemical outcome(s) in addition to adherence to dietary advice. Among those, six reported improvement in at least one chronic disease-related clinical or biochemical outcome in the intervention group. As mentioned earlier, these results should be interpreted with caution as several studies evaluated two or more clinical and/or biochemical outcomes.

Seventeen studies provided advice in order to induce changes other than diet such as physical activity, medication compliance, smoking cessation and blood glucose monitoring. All of these studies independently assessed adherence to dietary advice, but because those studies varied widely according to interventions provided and nature of the chronic diseases, we cannot conclude that adherence to dietary advice is improved when multifaceted interventions are provided.

 

Quality of the evidence

Despite a high number of included studies (n = 38), these studies varied widely according to interventions provided, measures of diet adherence, dietary advice, nature of the chronic diseases and duration of interventions and follow-up. The numbers of clients included in the review is impressive (9445), but the range of number of clients in each study was wide, varying from 7 to 5405 clients. Only 13 of the 38 included studies provided a power calculation (Aldarondo 1999; Assuncao 2010; Beasley 2008; Chiu 2010; French 2008; Hyman 2007; Jiang 2004; Meland 1994; Stewart 2005; Tsay 2003; Wong 2010; Wood 2008; Zhao 2004) and among them, 10 studies recruited the number of clients according to their power analysis (Aldarondo 1999; Assuncao 2010; Beasley 2008; French 2008; Jiang 2004; Meland 1994; Stewart 2005; Tsay 2003; Wong 2010; Zhao 2004).

While an elevated drop-out rate could be considered as an indirect measure of non-adherence, such as in studies of pharmaceutical interventions where participants who withdraw no longer have access to medication, it cannot be assumed that clients dropping out of dietary intervention studies are non-adherent to dietary advice. Most studies included in this review had a low drop-out rate. In fact, 19 studies reported a drop-out rate lower than 20% (9 of those had no drop-out). Nine studies had a drop-out rate of between 20% and 30% and only five studies had a drop-out rate over 30%. It was impossible to calculate the drop-out rate for six studies (Gans 1994; Gill 2010; Hsueh 2007; Jones 1986; Mahler 1999; McCulloch 1983). One study (Wood 2008) reported adherence for two populations, which explains why the total number of included studies adds up to 39, and not 38.

The majority of included studies were of poor methodological quality and/or poorly reported risk of bias elements. All included studies met less than five of the eight criteria of risk of bias (see Assessment of risk of bias in included studies). Among those eight criteria, three of them evaluated respectively the blinding of clients, providers and outcome assessors. Very few included studies met these criteria because blinding in the context of delivering a nutritional intervention is very difficult to achieve, even impossible in some designs. Unlike most pharmaceutical designs using placebo, both clients and providers from nutritional studies usually know which intervention is delivered.

A major challenge in the measurement of diet adherence is the correct estimation of dietary intake, as no method for accurate determination of dietary intake has been developed yet. In this review, 31 studies used self-reported measures of diet adherence while 6 studies assessed diet adherence using objective measures. Objective measures included serum micronutrients (e.g. potassium, sodium, phosphate) and interdialytic weight gain to evaluate respectively adherence to diet and to fluid-restricted diet in clients with renal diseases, and urinary electrolytes excretion (sodium, chloride) to evaluate adherence to a sodium-restricted diet in clients with hypertension. Those methods have been validated and are usually more reliable than self-reported measures. However, the assessment of many food and nutrient intakes cannot always be performed by objective measures, especially when dietary advice targets food groups (e.g. fruit and vegetables) rather than a specific nutrient (e.g. sodium). The Academy of Nutrition and Dietetics states that "total diet or overall pattern of food eaten is the most important focus of a healthful eating style" (JADA 2007). Consequently, most studies providing dietary advice focusing on a global healthy diet rather than a specific nutrient used self-reported methods such as dietary tools (e.g. food records, food frequency questionnaires and validated diet questionnaires or scales). Misreporting of dietary intake is a major issue and has been related to body mass index, age, sex, socio-economic status and education (Poslusna 2009). In addition, other sources of misreporting have been identified such as memory relapses, misrepresentation of portion size consumed, social desirability and daily dietary variability (Kumanyika 2000; Wilson 2005). Therefore, establishing validity and reliability of dietary tools is crucial in order to avoid inconsistent estimates of dietary intake leading to a high risk of bias. In this review, only 14 studies of 32 stated that the self-reported measures of diet adherence had been validated and/or shown to be reliable, suggesting that adherence to dietary advice in those studies could be biased. To gain a thorough understanding of adherence to dietary advice, both self-report and objective measures of adherence are needed. While objective measures provide information on food intake only, self-report measures also provide useful information on the circumstances of non-adherence. The latter is important for clinicians to understand the reasons why the client is non-adherent (which may include the clinicians’ lack of behavioral skills) and to promote a collaborative relationship that considers clients' values and preferences. More research is therefore needed to both develop standardized and validated self-report adherence measures and to identify more robust and objective measures of adherence to dietary advice.

 

Potential biases in the review process

Strengths of this review include the fact that we contacted many study authors during the data extraction process to gather additional information. The main reason was that some authors did not adequately describe the intervention provided in the intervention group and/or in the control/usual care group, in the published report. Additional information we received allowed us to better classify the included studies according to the intervention provided.

As expected, a limitation of this review is the definition of adherence to dietary advice. Adherence to dietary advice is a wide concept and includes many different measures including self-reported measures which are not always comparable. Accordingly, in this review, some included studies assessed adherence to dietary advice by reporting the proportion of clients achieving the dietary recommendations. However, the majority of included studies evaluated adherence to dietary advice by comparing the mean dietary intake between groups. These different ways to measure adherence to dietary advice suggest that there is a need to develop standardized and validated tools to assess adherence to dietary advice.

In this review, we only included studies clearly mentioning a measure of adherence to dietary advice in the title or the objective of the study and/or those reporting the proportion of clients adhering to dietary advice. Therefore, we excluded all studies reporting mean dietary intake between groups without specifically assessing adherence to dietary advice as a primary outcome. Despite an extensive search in standard databases as well as in the grey literature, we cannot exclude the possibility that we missed some studies measuring adherence to dietary advice if those studies were not indexed in bibliographic databases as reporting adherence or compliance.

We categorized interventions according to Michie et al (Michie 2011) intervention functions to simplify and structure the presentation of results and not to provide insights about which intervention function was most effective for enhancing adherence to dietary advice. Although two review authors assigned the interventions to the categories through consensus, the assignment was arbitrary and we cannot exclude the fact that others may have assigned interventions to other categories. However, it must be emphasized that the process did not interfere with the interpretation of results.

 

Agreements and disagreements with other studies or reviews

Few systematic reviews evaluated clients' adherence to recommendations in the context of preventing and/or managing chronic diseases. Among systematic reviews reporting the effectiveness of interventions to enhance adherence to dietary advice, none assessed the same criteria as this review, making comparisons difficult. For example, two systematic reviews included other components in the assessment of adherence in addition to diet, such as physical activity and medication (Matteson 2010; Greaves 2011). The evaluation of diet adherence alone for those studies was therefore impossible. Fappa et al (Fappa 2008) performed a non-systematic review on lifestyle interventions for enhancing adherence to diet and exercise in the management of the metabolic syndrome. However, dietary advice provided in the majority of included studies differed between the intervention and the control groups. Consequently, the effects of the intervention could not be isolated.

Burke 1997 conducted a non-systematic review of successful strategies to increase adherence to dietary advice in the context of CVD prevention. Among eleven included studies, interventions found to be effective to improve adherence to nutritional therapy were behavioural skill training, spouse support and self-efficacy enhancement.

Our results are consistent with those of Brownell and colleagues (Brownell 1995b) who performed an overview of studies with diet adherence data. They reported inconsistencies in methods and had difficulty interpreting results because of the broad variation of diseases covered and interventions provided. Similarly, Newell et al (Newell 2000) performed a non-systematic review of strategies for improving cardiovascular client compliance to non-pharmacologic treatments. No strong evidence was reported for the enhancement of dietary regime, and studies included were assessed as fair quality in term of study design. Those conclusions underline the fact that further good-quality studies assessing adherence to dietary advice for preventing and managing chronic diseases should be performed.

 

Authors' conclusions

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms

 

Implications for practice

Non-adherence to dietary advice represents one of the barriers to getting nutrition knowledge into practice, thereby potentially hampering the prevention of the onset or progression of many chronic diseases and ultimately, improved population well-being and health. This Cochrane review aimed to summarize, categorize and compare the effects of interventions for enhancing adherence to dietary advice for preventing and managing chronic diseases in adults. Some interventions such as telephone follow-up, video, contract, feedback and nutritional tools demonstrated a mixed effect on diet adherence as they showed some diet adherence outcomes favouring the intervention group compared to the control/usual care group but also no difference in some diet adherence outcomes between groups. Moreover, included studies differed widely according to interventions provided, measures of diet adherence, dietary advice, nature of the chronic diseases and duration of interventions and follow-up, making assessment of intervention versus intervention rather challenging. Therefore, this systematic review cannot draw firm conclusions from comparisons between interventions, but rather identifies a number of potentially-beneficial interventions that can be used in practice (telephone follow-up, video, contract, feedback and nutritional tools). Also, while the majority of multiple interventions have demonstrated a positive effect on diet adherence compared to a control/usual care group, none of the included studies assessed the same combination of interventions, making impossible the identification of the optimal combination of interventions to enhance adherence to dietary advice. Consequently, researchers, decision makers, health professionals and consumers remain with little practical guidance with regard to the best intervention for enhancing adherence to dietary advice. However, it may be argued that in health care, there is often no unique best option for either treatment or process of care, as these options may be influenced by clients’ preferences and values. Although longer-term, well-designed RCTs using improved methods for measuring diet adherence are needed, results of this systematic review provide options for both health professionals and consumers that may be used in practice. Interventions shown to be beneficial compared to a control/usual care group could be used depending on clients’ preferences, lifestyle and values, health professionals’ communication skills, and organisational context.

 
Implications for research

Evidence of the role of a healthy diet and/or specific nutrient intakes on the prevention and management of chronic diseases is well recognized. Further studies are now essential to refine methods for providing dietary advice and improve diet adherence in the context of chronic diseases. Several gaps in knowledge have been identified in this review regarding the effectiveness of interventions to enhance adherence to dietary advice for preventing and managing chronic diseases in adults:

  • Further good quality studies should be designed to minimize bias and to have an adequate sample size to detect significant differences between groups;
  • Further studies with a long-term duration, namely more than 12 months, and a follow-up evaluation are needed;
  • Further research should be designed with a comparison between an intervention group and a control/usual care group both providing the same dietary advice to capture the effect of the intervention only, without confounding factors;
  • Further studies need to define clearly the term 'adherence' and describe the intervention in detail. Moreover, there is a need to develop standardized and validated self-report tools and robust objective measures (e.g. biomarkers) to assess adherence to dietary advice;
  • Further studies should investigate the factors contributing to clients’ non-adherence to dietary advice in order to develop interventions to overcome barriers. These factors include psychosocial and environmental determinants, but also biological factors affecting food intake;
  • Moreover, perspectives from health professionals and clients about the interventions enhancing adherence to dietary advice should be studied with the aim of identifying those that are most implementable in practice and adaptable to local contexts (Desroches 2011).

 

Acknowledgements

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms

We thank the staff and editors of the Cochrane Consumers and Communication Review Group, especially Professor Adrian Edwards (Contact Editor for this review), Dr Megan Prictor (Managing Editor), Dr Sophie Hill (Coordinating Editor) and Mr John Kis-Rigo (Trials Search Coordinator). We also thank Dr Anik Giguere for her assistance with systematic review methods, Jayne Thirsk for her comments on the review and Narimane Toureche, Sarah-Maude Deschênes, Catherine Laramée, Vincent Hao May, Annabelle Fortier and Nadine Tremblay for their assistance with the selection of studies and/or data extraction and/or tables conception. Finally, we thank XiaoQiang Wang, Sumi Ross, Annette Bluemle, Amélie Trépanier, Sonia Pomerleau, Claire Glenton and Docent Suzana Nikolovska who assisted with translating publications from languages other than English (Chinese, Japanese, German, Spanish, Danish and Norwegian and Serbian).

 

Data and analyses

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms
Download statistical data

 
Comparison 1. Nutritional tools versus control in diet adherence

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Continuous data2Std. Mean Difference (IV, Random, 95% CI)Totals not selected

    1.1 Adherence to energy intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.2 Adherence to protein intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.3 Adherence to fat intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.4 Adherence to carbohydrate intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.5 Adherence to cholesterol intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.6 Adherence to fiber intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.7 Adherence to sodium intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.8 Adherence to fruit intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.9 Adherence to vegetable intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.10 Adherence to sweet food intake at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.11 Adherence to energy intake at 12 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.12 Adherence to fat intake at 12 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

 
Comparison 2. Multiple interventions versus control in diet adherence

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Continuous data4Std. Mean Difference (IV, Random, 95% CI)Totals not selected

    1.1 Adherence to sodium-restricted diet at 3 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.2 Adherence to diet at 3 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.3 Adherence to fluid-restricted diet at 1 month
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.4 Adherence to fluid-restricted diet at 3 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.5 Adherence to fluid-restricted diet at 6 months
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.6 Non-adherence to diet (days) at 7 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.7 Non-adherence to diet (days) at 13 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.8 Non-adherence to diet (degree) at 7 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.9 Non-adherence to diet (degree) at 13 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.10 Non-adherence to fluid-restricted diet (days) at 7 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.11 Non-adherence to fluid-restricted diet (days) at 13 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.12 Non-adherence to fluid-restricted diet (degree) at 7 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

    1.13 Non-adherence to fluid-restricted diet (degree) at 13 weeks
1Std. Mean Difference (IV, Random, 95% CI)0.0 [0.0, 0.0]

 2 Dichotomous data5Risk Ratio (M-H, Random, 95% CI)Totals not selected

    2.1 Adherence to sodium-restricted diet at 18 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.2 Adherence to fat intake at 3 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.3 Adherence to saturated fat intake at 3 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.4 Adherence to unsaturated fat intake at 3 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.5 Adherence to carbohydrate intake at 3 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.6 Adherence cholesterol intake at 3 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.7 Adherence to saturated fat intake at 15 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.8 Adherence to fat intake at 15 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.9 Adherence to unsaturated fat intake at 15 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.10 Adherence to carbohydrate intake at 15 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.11 Adherence to fiber intake at 15 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.12 Adherence to cholesterol intake at 15 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.13 Adherence to phosphate-restricted diet at 3 months
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.14 Adherence to saturated fat intake at 1 year - CHD patients
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.15 Adherence to oily fish intake at 1 year - CHD patients
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.16 Adherence to fish intake at 1 year - CHD patients
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.17 Adherence to fruit and vegetable intake at 1 year - CHD patients
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.18 Adherence to oily fish intake at 1 year - high risk CHD patients
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.19 Adherence to fish intake at 1 year - high-risk CHD patients
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.20 Adherence to fruit and vegetable intake at 1 year - high-risk CHD patients
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.21 Adherence to diet at 4 weeks
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

    2.22 Adherence to diet at 12 weeks
1Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

 

Appendices

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms
 

Appendix 1. PubMed search strategy

#1   Patient compliance[MH:NOEXP]
#2   Complian*[TIAB] OR Comply*[TIAB] OR Complied[TIAB] OR Adher*[TIAB] OR Noncomplian*[TIAB] OR Nonadher*[TIAB]
#3   #1 OR #2
#4   Diet[MH]
#5   Diet therapy[MH]
#6   Nutrition assessment[MH]
#7   Food habits[MH]
#8   Nutrition policy[MH]
#9   Nutritional requirements[MH]
#10 Nutrition therapy[MH:NOEXP]
#11 Diet therapy[SH]
#12 Diet[TIAB] OR Diets[TIAB] OR Dieta*[TIAB] OR Diete*[TIAB] OR Dieti*[TIAB] OR Nutrition*[TIAB] OR Food habit*[TIAB] OR Feeding behaviour*[TIAB] OR Eating behaviour*[TIAB]
#13  #4 OR #5 OR #6 OR #7 OR #8 OR #9 OR #10 OR #11 OR #12
#14  Randomized controlled trial[PT]
#15  Controlled clinical trial[PT]
#16  Randomized[TIAB]
#17  Randomly[TIAB]
#18  Trial[TIAB]
#19  Groups[TIAB]
#20  Placebo[TIAB]
#21  Drug therapy[SH]
#22  #14 OR #15 OR #16 OR #17 OR #18 OR #19 OR #20 OR #21
#23   Animals[MH] NOT Humans[MH]
#24   (#3 AND #13 AND #22) NOT #23

 

Appendix 2. EMBASE search strategy

#1 'Patient compliance'/de

#2 (Complian* OR Comply* OR Complied OR Adher* OR Noncomplian* OR Nonadher*):ti,ab

#3 #1 OR #2

#4 Diet/exp

#5 'Diet therapy'/exp

#6 'Nutritional assessment'/de

#7 'Feeding behavior'/exp

#8 'Nutritional requirement'/exp

#9 #4 OR #5 OR #6 OR #7 OR #8

#10 (Diet* OR Nutrition* OR 'Food habit' OR 'Food habits' OR 'Feeding behavior' OR 'Feeding behaviors' OR 'Eating behavior' OR 'Eating behaviors'):ti,ab

#11 #9 OR #10

#12 #3 AND #11

#13 'Randomized controlled trial'/de

#14 'Controlled clinical trial'/de

#15 'Single blind procedure'/de OR 'Double blind procedure'/de

#16 'Crossover procedure'/

#17 Random*:ti,ab

#18 Placebo*:ti,ab

#19 ((singl* or doubl*) adj (blind* or mask*)):ti,ab

#20 (crossover or 'cross over' or factorial* or 'latin square'):ti,ab

#21 (assign* or allocat* or volunteer*):ti,ab

#22 #13 OR #14 OR #15 OR #16 OR #17 OR #18 OR #19 OR #20 OR #21

#23 (Animal/ OR Nonhuman) NOT Human/

#24 #22 NOT #23

#25 #12 AND #24

 

Appendix 3. CINAHL search strategy

S1 MH "Patient Compliance"

S2 TI (Complian* OR Comply* OR Complied OR Adher* OR Noncomplian* OR Nonadher*) OR AB (Complian* OR Comply* OR Complied OR Adher* OR Noncomplian* OR Nonadher*)

S3 S1 OR S2

S4 MH "Diet+"

S5 MH "Diet therapy+"

S6 MH "Nutritional assessment"

S7 MH "Food habits"

S8 MH "Eating behavior+"

S9 MH "Nutrition policy+"

S10 MH "Nutritional requirement+"

S11 MW "DH"

S12 TI (Diet* OR Nutrition* OR "Food habit*" OR "Feeding behavior*" OR "Eating behavior*") OR AB (Diet* OR Dieti* OR Nutrition* OR "Food habit*" OR "Feeding behavior*" OR "Eating behavior*")

S13 S4 OR S5 OR S6 OR S7 OR S8 OR S9 OR S10 OR S11 OR S12

S14 S2 AND S13

S15 Randomi?ed controlled Trial*

S16 PT "Clinical Trial"

S17 MH "Clinical Trials +"

S18 MH "Random Assignment"

S19 MH "Placebos"

S20 MH "Quantitative studies"

S21 TI (random* OR trial or groups or placebo*) OR AB (random* OR trial or groups or placebo*)

S22 TI (singl* or doubl* or tripl* or trebl*) and TI (blind* or mask*)

S23 AB (singl* or doubl* or tripl* or trebl*) and AB (blind* or mask*)

S24 S15 OR S16 OR S17 OR S18 OR S19 OR S20 OR S21 OR S22 OR S23

S25 S14 AND S24

S26 S25 (Limiters - Exclude Medline records)

 

Appendix 4. PsycINFO search strategy

#1 (complian* or comply* or complied or adher* or noncomplian* or nonadheren*)

#2 (diet* or nutrition* or "food habit" or "food habits" or "food intake" or "food intakes" or "eating behavior" or "eating behaviors" OR "feeding behavior" OR "feeding behaviors").

#3 #1 AND #2

#4 Random*

#5 Trial*

#6 Control*

#7 Placebo*

#8 ((singl* or doubl* or trebl* or tripl*) and (blind* or mask*))

#9 "cross over" or crossover or factorial* or "latin square"

#10 assign* or allocat* or volunteer*

#11 it = "treatment effectiveness evaluation"

#12 it = "mental health program evaluation"

#13 it = "Experimental design"

#14 #4 OR #5 OR #6 OR #7 OR #8 OR #9 OR #10 OR #11 OR #12 OR #13

#15 #3 AND #14

 

Appendix 5. The Cochrane Library search strategy

#1 (Complian* OR Comply* OR Complied OR Adher* OR Noncomplian* OR Nonadher*):ti,ab,kw

#2 (Diet* OR Nutrition* OR "Food habit*" OR "Feeding behavior*" OR "Eating behavior*"):ti,ab,kw

#3 MeSH descriptor Diet explode all trees

#4 MeSH descriptor Diet Therapy explode all trees

#5 #2 OR #3 OR #4

#6 #1 AND #5

 

Appendix 6. Methods for potential application in future updates of the review

Unit of analysis issues

We will meta-analyse cluster RCTs with non-cluster RCTs after inflating the standard errors to account for clustering. If cluster RCTs are included, we will request the intracluster correlation coefficient (ICC) from the study authors. If the ICC is not available, it will be imputed with external estimates obtained from similar studies. The ICC will then be used to calculate the design effect in order to obtain an inflated standard error that accounts for clustering by multiplying the standard error of the effect estimate (from an analysis ignoring clustering) by the square root of the design effect. We will also perform sensitivity analyses to assess how sensitive results are to reasonable changes in ICC imputation.

Dealing with missing data

Where data are missing, we will attempt to contact study authors. We will conduct an intention-to-treat (ITT) analysis where possible; otherwise data will be analysed as reported. Loss to follow-up will be documented and assessed as a source of potential bias. We will perform sensitivity analyses based on consideration of 'best-case' and 'worst-case' scenarios (CCCRG 2010; Gamble 2005). The 'best-case' scenario is that all missing outcomes in the experimental intervention group had good outcomes, and all those missing in the control intervention group had poor outcomes; the 'worst-case' scenario is the reverse.

Assessment of heterogeneity

Where meta-analysis is possible, we will assess statistical heterogeneity between trials using the Chi2 statistic and I2 statistic. A Chi2 P value of less than 0.10 or an I2 value equal to or more than 50% will be considered to indicate substantial heterogeneity. If heterogeneity is identified, we will undertake subgroup analysis to investigate its possible source. We will conduct a meta-regression if there are enough studies to assess the effect of the possible sources of heterogeneity.

Data synthesis

We will group data with respect to participants' health condition (prevention versus management of chronic diseases). We will analyse included studies to determine whether there are studies sufficiently similar in participants' characteristics (e.g. age, gender), study design (RCT, cluster RCT), type of intervention (e.g. directed towards client, family or non-family caregiver), environmental setting (e.g. outpatient, workplace, or other community settings), and outcome measurement to allow for a meta-analysis of their combined data. If studies are sufficiently similar, we will conduct meta-analyses using a random-effects model. If studies are too heterogeneous, we will present a descriptive review of included studies using a narrative along with extracted data in tables and figures.

Subgroup analysis and investigation of heterogeneity

If enough studies are found to justify subgroup analyses, the following subgroups could be investigated using random-effects meta-regression:

  • Type of intervention (e.g. directed towards client, family or non-family caregiver); and
  • Characteristics of participants (e.g. age, gender, socioeconomic status, immigrant status).

Sensitivity analysis

We will conduct a primary analysis with studies which we consider to have a low risk of bias (i.e. those receiving a 'low risk' rating for the criteria of sequence generation and allocation concealment). Sensitivity analyses will also be performed with all included studies in order to show how conclusions might be affected if studies at high risk of bias were appropriate in order to explore the influence of the following factors on effect size:

  • excluding unpublished studies;
  • excluding studies that do not provide the drop out rate;
  • excluding any large studies to establish how they impact on the results;
  • excluding studies using the following filters; language of publication, source of funding (industry versus other);
  • excluding studies based on weak-evidence advice (e.g. not coming from practice guidelines).

 

Contributions of authors

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms

SD coordinated and contributed to all stages of the review.

AL performed the search strategy, identified eligible studies, extracted data, performed analysis and interpreted result and wrote the first draft of the review.

ST assisted with statistical analyses, contributed to the writing of the review.

SR developed the search strategy, contributed to the writing of the review.

KG contributed to the protocol development and to the writing of the review.

FL contributed to the protocol development and to the writing of the review.

 

Declarations of interest

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms

None known.

 

Sources of support

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms
 

Internal sources

  • No sources of support supplied

 

External sources

  • Canadian Institutes of Health Research, Canada.
    Salary of Annie Lapointe

 

Differences between protocol and review

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. Contributions of authors
  12. Declarations of interest
  13. Sources of support
  14. Differences between protocol and review
  15. Index terms

The protocol was published in 2010 (Desroches 2010).

Types of interventions: Multiple interventions are now defined as those with two or more interventions.

Pubmed search strategy: Food habit*[TIAB] or Feeding behaviour*[TIAB] or Eating behaviour*[TIAB] were added to the Pubmed search strategy.

Assessment of reporting biases: publication bias using funnel plot was not explored since multiple adherence outcome measures were reported in several studies and could not be pooled together.

* Indicates the major publication for the study

References

References to studies included in this review

  1. Top of page
  2. AbstractRésumé scientifique
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Characteristics of studies
  17. References to studies included in this review
  18. References to studies excluded from this review
  19. References to studies awaiting assessment
  20. References to ongoing studies
  21. Additional references
  22. References to other published versions of this review
Aldarondo 1999 {published and unpublished data}
  • Aldarondo F. Adherence among individuals in an exercise, nutrition, and weight loss program (PhD thesis). University of Indiana. US: ProQuest Information & Learning, 1999; Vol. 60.
Arcand 2005 {published and unpublished data}
  • Arcand JA, Brazel S, Joliffe C, Choleva M, Berkoff F, Allard JP, et al. Education by a dietitian in patients with heart failure results in improved adherence with a sodium-restricted diet: a randomized trial. American Heart Journal 2005;150:716.
Assuncao 2010 {published and unpublished data}
  • Assuncao MC, Gigante DP, Cardoso MA, Sartorelli DS, Santos IS. Randomized, controlled trial promotes physical activity and reduces consumption of sweets and sodium among overweight and obese adults. Nutrition Research 2010;30:541-9.
Baraz 2010 {published and unpublished data}
Beasley 2008 {published and unpublished data}
  • Beasley JM, Riley WT, Davis A, Singh J. Evaluation of a PDA-based dietary assessment and intervention program: a randomized controlled trial. Journal of the American College of Nutrition 2008;27:280-6.
Becker 1998 {published data only}
  • Becker DM, Raqueno JV, Yook RM, Kral BG, Blumenthal RS, Moy TF, et al. Nurse-mediated cholesterol management compared with enhanced primary care in siblings of individuals with premature coronary disease. Archives of Internal Medicine 1998;158:1533-9.
Bennett 1986 {published and unpublished data}
Blanson 2009 {published and unpublished data}
  • Blanson Henkemans OA, van der Boog PJ, Lindenberg J, van der Mast CA, Neerincx MA, Zwetsloot-Schonk BJ. An online lifestyle diary with a persuasive computer assistant providing feedback on self-management. Technology and Health Care 2009;17:253-67.
Chen 2006 {published data only}
Chiu 2010 {published data only}
  • Chiu CW, Wong FK. Effects of 8 weeks sustained follow-up after a nurse consultation on hypertension: a randomised trial. International Journal of Nursing Studies 2010;47:1374-82.
Conrad 2000 {published data only}
  • Conrad BC, Glanville NT, Raine-Travers KD. Adherence to a very low fat diet for cardiac rehabilitation patients. Canadian Journal of Dietetic Practice and Research 2000;61:193-5.
Cummings 1981 {published and unpublished data}
  • Cummings KM, Becker MH, Kirscht JP, Levin NW. Intervention strategies to improve compliance with medical regimens by ambulatory hemodialysis patients. Journal of Behavioral Medicine 1981;4:111-27.
French 2008 {published data only}
Gans 1994 {published data only}
  • Gans KM, Lapane KL, Lasater TM, Carleton RA. Effects of intervention on compliance to referral and lifestyle recommendations given at cholesterol screening programs. American Journal of Preventive Medicine 1994;10:275-82.
Gill 2010 {published and unpublished data}
  • Gill CE, Cook EA, Smith CL, Domos CA, Delmonico MJ, Lofgren IE. Dietary Approaches to Stop Hypertension diet compliance decreases coronary heart disease risk in overweight and obese college-aged women. Journal of the American Dietetic Association 2010;110:A-116.
Grace 1996 {published and unpublished data}
  • Grace C, Summerbell C. Does provision of additional dietary information affect actual or only reported compliance to a low-fat diet over 12 weeks in hyperlipidaemic individuals? Report of a pilot study. Journal of Human Nutrition and Dietetics 1996;9:303-7.
Gucciardi 2007 {published and unpublished data}
  • Gucciardi E, Demelo M, Lee RN, Grace SL. Assessment of two culturally competent diabetes education methods: individual versus individual plus group education in Canadian Portuguese adults with type 2 diabetes. Ethnicity and Health 2007;12:163-87.
Hsueh 2007 {published data only}
  • Hsueh H. Compliance with dietary recommendations in adults with irritable bowel syndrome (PhD thesis). University of Washington. University of Washington, 2007.
Hyman 2007 {published data only}
Jiang 2004 {published and unpublished data}
  • Jiang X. The effect of a nurse-led cardiac rehabilitation programme on patients with coronary heart disease in Chengdu, China (PhD thesis). The Hong Kong Polytechnic University. Hong Kong Polytechnic University (People's Republic of China), 2004.
  • Jiang X, Sit JW, Wong TK. A nurse-led cardiac rehabilitation programme improves health behaviours and cardiac physiological risk parameters: evidence from Chengdu, China. Health Technology Assessment 2007;16:1886-97.
Jones 1986 {published data only}
  • Jones SE, Owens HM, Bennett GA. Does behaviour therapy work for dietitians? An experimental evaluation of the effects of three procedures in a weight reduction clinic. Human Nutrition: Applied Nutrition 1986;40:272-81.
Kendall 1987 {published and unpublished data}
  • Kendall PA, Jansen CM, Sjogren DD, Jansen GR. A comparison of nutrient-based and exchange-group methods of diet instruction for patients with noninsulin-dependent diabetes. Annals of Surgery 1987;45:625-37.
Laitinen 1993 {published and unpublished data}
  • Laitinen JH, Ahola IE, Sarkkinen ES, Winberg RL, Harmaakorpi-Iivonen PA, Uusitupa MI. Impact of intensified dietary therapy on energy and nutrient intakes and fatty acid composition of serum lipids in patients with recently diagnosed non-insulin-dependent diabetes mellitus. Journal of the American Dietetic Association 1993;93:276-83.
Logan 2010 {published and unpublished data}
  • Logan KJ, Woodside JV, Young IS, McKinley MC, Perkins-Porras L, McKeown PP. Adoption and maintenance of a Mediterranean diet in patients with coronary heart disease from a Northern European population: a pilot randomised trial of different methods of delivering Mediterranean diet advice. Journal of Human and Dietetics 2010;23:30-7.
Mahler 1999 {published and unpublished data}
  • Mahler HI, Kulik JA, Tarazi RY. Effects of a videotape information intervention at discharge on diet and exercise compliance after coronary bypass surgery. Journal of Cardiopulmonary Rehabilitation 1999;19:170-7.
McCulloch 1983 {published data only}
  • McCulloch DK, Mitchell RD, Ambler J, Tattersall RB. Influence of imaginative teaching of diet on compliance and metabolic control in insulin dependent diabetes. British Medical Journal 1983;287:1858-61.
Meland 1994 {published and unpublished data}
  • Meland E, Laerum E, Ulvik RJ. Salt restriction in hypertension: the effect of dietary advice and self monitoring of chloride concentration in urine. Scandinavian Journal of Clinical and Laboratory Investigation 1994;54:399-404.
Micco 2007 {published data only}
  • Micco N, Gold B, Buzzell P, Leonard H, Pintauro S, Harvey-Berino J. Minimal in-person support as an adjunct to internet obesity treatment. Annals of Behavioral Medicine 2007;33:49-56.
Miller 1988 {published data only}
  • Miller P, Wikoff R, Garrett M J, McMahon M, Smith T. Regimen compliance two years after myocardial infarction. Nursing Research 1990;39:333-6.
  • Miller P, Wikoff R, McMahon M, Garrett M J, Ringel K. Influence of a nursing intervention on regimen adherence and societal adjustments postmyocardial infarction. Nursing Research 1988;37:297-302.
  • Miller P, Wikoff R, McMahon M, Garrett MJ, Ringel K, Collura D, et al. Personal adjustments and regimen compliance 1 year after myocardial infarction. Heart and Lung 1989;18:339-46.
Morey 2008 {published data only}
  • Morey B, Walker R, Davenport A. More dietetic time, better outcome? A randomized prospective study investigating the effect of more dietetic time on phosphate control in end-stage kidney failure haemodialysis patients. Nephron Clinical Practice 2008;109:c173-80. [DOI: 10.1159/000145462]
Racelis 1998 {published data only}
  • Racelis MC, Lombardo K, Verdin J. Impact of telephone reinforcement of risk reduction education on patient compliance. Journal of Vascular Nursing 1998;16:16-20.
Ryan 2002 {published and unpublished data}
  • Ryan EA, Todd KR, Estey A, Cook B, Pick M. Diabetes education evaluation: a prospective outcome study. Canadian Journal of Diabetes 2002;26:113-9.
Scisney-Matlock 2006 {published data only}
  • Scisney-Matlock M, Glazewki L, McClerking C, Kachorek L. Development and evaluation of DASH diet tailored messages for hypertension treatment. Applied Nursing Research 2006;19:78-87.
Stewart 2005 {published and unpublished data}
  • Stewart A, Noakes T, Eales C, Shepard K, Becker P, Veriawa Y. Adherence to cardiovascular risk factor modification in patients with hypertension. Cardiovascular Journal of South Africa 2005;16:102-7.
Tsay 2003 {published data only}
Wong 2010 {published and unpublished data}
  • Chow SKY. The effects of a nurse-led case management programme on patients undergoing peritoneal dialysis: a randomized controlled trial (PhD thesis). The Hong Kong Polytechnic University 2006.
  • Wong FK, Chow SK, Chan TM. Evaluation of a nurse-led disease management programme for chronic kidney disease: a randomized controlled trial. International Journal of Nursing Studies 2010;47:268-78.
Wood 2008 {published data only}
  • Wood DA, Kotseva K, Connolly S, Jennings C, Mead A, Jones J, et al. Nurse-coordinated multidisciplinary, family-based cardiovascular disease prevention programme (EUROACTION) for patients with coronary heart disease and asymptomatic individuals at high risk of cardiovascular disease: a paired, cluster-randomised controlled trial. The Lancet 2008;371:1999-2012.
Zhao 2004 {published data only}
  • Zhao Y. Effects of a discharge planning intervention for elderly patients with coronary heart disease in Tianjin, China: a randomized controlled trial (PhD thesis). Hong Kong Polytechnic University (People's Republic of China) 2004.

References to studies excluded from this review

  1. Top of page
  2. AbstractRésumé scientifique
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Characteristics of studies
  17. References to studies included in this review
  18. References to studies excluded from this review
  19. References to studies awaiting assessment
  20. References to ongoing studies
  21. Additional references
  22. References to other published versions of this review
Abramson 1980 {published data only}
  • Abramson R, Garg M, Cioffari A, Rotman PA. An evaluation of behavioral techniques reinforced with an anorectic drug in a double-blind weight loss study. Journal of Clinical Psychiatry 1980;41:234-7.
Agras 1996 {published data only}
Ammerman 2003 {published data only}
  • Ammerman AS, Keyserling TC, Atwood JR, Hosking JD, Zayed H, Krasny C. A randomized controlled trial of a public health nurse directed treatment program for rural patients with high blood cholesterol. Preventive Medicine 2003;36:340-51.
Arnaud-Battandier 1999 {published data only}
  • Arnaud-Battandier F, Lauque S, Paintin M, Mansourian R, Vellas B, Guigoz Y. MNA and nutritional intervention. Nestlé Nutrition Workshop Series Clinical and Performance Programme 1999;1:131-8; discussion 138-40.
Ashurst 2003 {published data only}
  • Ashurst I de B, Dobbie H. A randomized controlled trial of an educational intervention to improve phosphate levels in hemodialysis patients. Journal of Renal Nutrition 2003;13:267-74.
Atwood 1992 {published data only}
  • Atwood JR, Aickin M, Giordano L, Benedict J, Bell M, Ritenbaugh C, et al. The effectiveness of adherence intervention in a colon cancer prevention field trial. Preventive Medicine 1992;21:637-53.
Babamoto 2009 {published data only}
  • Babamoto KS, Sey KA, Camilleri AJ, Karlan VJ, Catalasan J, Morisky DE. Improving diabetes care and health measures among hispanics using community health workers: results from a randomized controlled trial. Health Education and Behavior 2009;36:113-26.
Basler 1982 {published data only}
  • Basler HD, Brinkmeier U, Buser K, Haehn KD, Molders-Kober R. Psychological group treatment of essential hypertension in general practice. British Journal of Clinical Psychology 1982;21 (Pt 4):295-302.
Baum 1991 {published data only}
  • Baum JG, Clark HB, Sandler J. Preventing relapse in obesity through posttreatment maintenance systems: comparing the relative efficacy of two levels of therapist support. Journal of Behavioral Medicine 1991;14:287-302.
Befort 2008 {published data only}
  • Befort CA, Nollen N, Ellerbeck EF, Sullivan DK, Thomas JL, Ahluwalia JS. Motivational interviewing fails to improve outcomes of a behavioral weight loss program for obese African American women: a pilot randomized trial. Journal of Behavioral Medicine 2008;31:367-77.
Berra 2007 {published data only}
  • Berra K, Ma J, Klieman L, Hyde S, Monti V, Guardado A, et al. Implementing cardiac risk-factor case management: lessons learned in a county health system. Critical Patway in Cardiology 2007:173-9.
Berteus 2008 {published data only}
  • Berteus Forslund H, Klingstrom S, Hagberg H, Londahl M, Torgerson JS, Lindroos AK. Should snacks be recommended in obesity treatment? A 1-year randomized clinical trial. European Journal of Clinical Nutrition 2008;62:1308-17.
Bertram 1990 {published data only}
Boeka 2010 {published data only}
  • Boeka AG, Prentice-Dunn S, Lokken KL. Psychosocial predictors of intentions to comply with bariatric surgery guidelines. Psychology, Health and Medicine 2010;15:188-97.
Borg 2002 {published data only}
  • Borg P, Kukkonen-Harjula K, Fogelholm M, Pasanen M. Effects of walking or resistance training on weight loss maintenance in obese, middle-aged men: a randomized trial. International Journal of Obesity 2002;26:676-83.
Bosworth 2008 {published data only}
  • Bosworth HB, Olsen MK, Neary A, Orr M, Grubber J, Svetkey L, et al. Take Control of Your Blood Pressure (TCYB) study: a multifactorial tailored behavioral and educational intervention for achieving blood pressure control. Patient Education and Counseling 2008;70:338-47.
Brekke 2003 {published data only}
  • Brekke HK, Jansson PA, Mansson JE, Lenner RA. Lifestyle changes can be achieved through counseling and follow-up in first-degree relatives of patients with type 2 diabetes. Journal of the American Dietetic Association 2003;103:835-43.
Brekke 2005a {published data only}
  • Brekke HK, Lenner RA, Taskinen MR, Mansson JE, Funahashi T, Matsuzawa Y, et al. Lifestyle modification improves risk factors in type 2 diabetes relatives. Diabetes Research and Clinical Practice 2005;68:18-28.
Brekke 2005b {published data only}
  • Brekke HK, Jansson PA, Lenner RA. Long-term (1- and 2-year) effects of lifestyle intervention in type 2 diabetes relatives. Diabetes Research and Clinical Practice 2005;70:225-34.
Brekke 2009 {published data only}
  • Brekke HK, Sunesson A, Lenner RA. Unannounced telephone interviews: a useful and positively received tool in the reinforcement of lifestyle intervention. Patient Preference and Adherence 2009;3:357-62.
Broekhuizen 2010 {published data only}
  • Broekhuizen K, van Poppel MN, Koppes LL, Brug J, van Mechelen W. A tailored lifestyle intervention to reduce the cardiovascular disease risk of individuals with Familial Hypercholesterolemia (FH): design of the PRO-FIT randomised controlled trial. BMC Public Health 2010;10:69.
Bruckert 2008 {published data only}
  • Bruckert E, Giral P, Paillard F, Ferrieres J, Schlienger JL, Renucci JF, et al. Effect of an educational program (PEGASE) on cardiovascular risk in hypercholesterolaemic patients. Cardiovascular Drugs and Therapy 2008;22:495-505.
Burke 2005 {published and unpublished data}
  • Burke LE, Dunbar-Jacob J, Orchard TJ, Sereika SM. Improving adherence to a cholesterol-lowering diet: a behavioral intervention study. Patient Education and Counseling 2005;57:134-42.
Burke 2006a {published data only}
  • Burke LE, Sereika S, Choo J, Warziski M, Music E, Styn M, et al. Ancillary study to the PREFER trial: a descriptive study of participants' patterns of self-monitoring--rationale, design and preliminary experiences. Contemporary Clinical Trials 2006;27:23-33.
Burke 2006b {published data only}
  • Burke LE, Choo J, Music E, Warziski M, Styn MA, Kim Y, et al. PREFER study: a randomized clinical trial testing treatment preference and two dietary options in behavioral weight management: rationale, design and baseline characteristics. Contemporary Clinical Trials 2006;27:34-48.
Burke 2007 {published data only}
  • Burke LE, Hudson AG, Warziski MT, Styn MA, Music E, Elci OU, et al. Effects of a vegetarian diet and treatment preference on biochemical and dietary variables in overweight and obese adults: a randomized clinical trial. American Journal of Clinical Nutrition 2007;86:588-96.
Burke 2008 {published data only}
  • Burke LE, Sereika SM, Music E, Warziski M, Styn MA, Stone A. Using instrumented paper diaries to document self-monitoring patterns in weight loss. Contemporary Clinical Trials 2008;29:182-93.
Burke 2010 {published data only}
Burkett 1990 {published data only}
  • Burkett PA, Southard DR, Herbert WG, Walberg J. Frequent cholesterol feedback as an aid in lowering cholesterol levels. Journal of Cardiopulmonary Rehabilitation 1990:141-6.
Campbell 1984 {published data only}
  • Campbell DF, Dixon JK, Sanderford LD, Denicola MA. Relaxation: its effect on the nutritional status and performance status of clients with cancer. Journal of the American Dietetic Association 1984;84:201-4.
Campbell 1990 {published and unpublished data}
Campbell 1998 {published data only}
Cangiano 1991 {published data only}
  • Cangiano C, Ceci F, Cairella M, Cascino A, Del Ben M, Laviano A, et al. Effects of 5-hydroxytryptophan on eating behavior and adherence to dietary prescriptions in obese adult subjects. Advances in Experimental Medicine and Biology 1991;294:591-3.
Cangiano 1992 {published data only}
  • Cangiano C, Ceci F, Cascino A, Del Ben M, Laviano A, Muscaritoli M, et al. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan. American Journal of Clinical Nutrition 1992;56:863-7.
Cangiano 1998 {published data only}
  • Cangiano C, Laviano A, Del Ben M, Preziosa I, Angelico F, Cascino A, et al. Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients. International Journal of Obesity 1998;22:648-54.
Carels 2005 {published data only}
  • Carels RA, Darby LA, Douglass OM, Cacciapaglia HM, Rydin S. Education on the glycemic index of foods fails to improve treatment outcomes in a behavioral weight loss program. Eating Behaviors 2005;6:145-50.
Carels 2005a {published data only}
  • Carels RA, Darby LA, Rydin S, Douglass OM, Cacciapaglia HM, O'Brien WH. The relationship between self-monitoring, outcome expectancies, difficulties with eating and exercise, and physical activity and weight loss treatment outcomes. Annals of Behavioral Medicine 2005;30:182-90.
Carson 1988 {published data only}
Casebeer 1999 {published data only}
  • Casebeer LL, Klapow JC, Centor RM, Stafford MA, Renkl LA, Mallinger AP, et al. An intervention to increase physicians' use of adherence-enhancing strategies in managing hypercholesterolemic patients. Academic Medicine 1999;74:1334-9.
Cegala 2000 {published data only}
Chang 2009 {published data only}
  • Chang MW, Brown R, Nitzke S. Participant recruitment and retention in a pilot program to prevent weight gain in low-income overweight and obese mothers. BMC Public Health 2009;9:424.
Cheyette 2007 {published data only}
  • Cheyette C. Weight no more: a randomised controlled trial for people with type 2 diabetes on insulin therapy. Practical Diabetes International 2007:450-6.
Chlebowski 1993 {published data only}
  • Chlebowski RT, Blackburn GL, Buzzard IM, Rose DP, Martino S, Khandekar JD, et al. Adherence to a dietary fat intake reduction program in postmenopausal women receiving therapy for early breast cancer. The Women's Intervention Nutrition Study. Journal of Clinical Oncology 1993;11:2072-80.
Costa 2008 {published data only}
  • Costa e Silva R, Pellanda L, Portal V, Maciel P, Furquim A, Schaan B. Transdisciplinary approach to the follow-up of patients after myocardial infarction. Clinics 2008;63:489-96.
Darlington 1986 {published data only}
Davidson 1996 {published data only}
  • Davidson MH, Kong JC, Drennan KB, Story K, Anderson GH. Efficacy of the National Cholesterol Education Program Step I diet. A randomized trial incorporating quick-service foods. Archives of Internal Medicine 1996;156:305-12.
Dechamps 2009 {published data only}
  • Dechamps A, Gatta B, Bourdel-Marchasson I, Tabarin A, Roger P. Pilot study of a 10-week multidisciplinary Tai Chi intervention in sedentary obese women. Clinical Journal of Sport Medicine 2009;19:49-53.
Del 2009 {published data only}
  • Del Corral P, Chandler-Laney PC, Casazza K, Gower BA, Hunter GR. Effect of dietary adherence with or without exercise on weight loss: a mechanistic approach to a global problem. The Journal of Clinical Endocrinology and Metabolism 2009;94:1602-7.
Demark-Wahnefried 2006 {published data only}
  • Demark-Wahnefried W, Clipp EC, Morey MC, Pieper CF, Sloane R, Snyder DC, et al. Lifestyle intervention development study to improve physical function in older adults with cancer: Outcomes from project LEAD. Journal of Clinical Oncology 2006:3465-73.
Dennis 2001 {published data only}
  • Dennis KE, Tomoyasu N, McCrone SH, Goldberg AP, Bunyard L, Qi BB. Self-efficacy targeted treatments for weight loss in postmenopausal women. An International Journal 2001;15:259-76.
De Zwaan 2005 {published data only}
  • De Zwaan M, Mitchell JE, Crosby RD, Mussell MP, Raymond NC, Specker SM, et al. Short-term cognitive behavioral treatment does not improve outcome of a comprehensive very-low-calorie diet program in obese women with binge eating disorder. Behavior Therapy 2005:89-99.
Digenio 2009 {published data only}
  • Digenio AG, Mancuso JP, Gerber RA, Dvorak RV. Comparison of methods for delivering a lifestyle modification program for obese patients: a randomized trial. Annals of Internal Medicine 2009;150:255-62.
Domenech 1995 {published data only}
  • Domenech MI, Assad D, Mazzei ME, Kronsbein P, Gagliardino JJ. Evaluation of the effectiveness of an ambulatory teaching/treatment programme for non-insulin dependent (type 2) diabetic patients. Acta Diabetologica 1995;32:143-7.
Donnelly 2003 {published data only}
  • Donnelly JE, Kirk EP, Jacobsen DJ, Hill JO, Sullivan DK, Johnson SL. Effects of 16 mo of verified, supervised aerobic exercise on macronutrient intake in overweight men and women: the Midwest Exercise Trial. American Journal of Clinical Nutrition 2003;78:950-6.
Dyson 1997 {published data only}
  • Dyson PA, Hammersley MS, Morris RJ, Holman RR, Turner RC. The Fasting Hyperglycaemia Study: II. Randomized controlled trial of reinforced healthy-living advice in subjects with increased but not diabetic fasting plasma glucose. Metabolism 1997;46:50-5.
Eriksson 2009 {published data only}
  • Eriksson MK, Franks PW, Eliasson M. A 3-year randomized trial of lifestyle intervention for cardiovascular risk reduction in the primary care setting: the Swedish Bjorknas study. PLOS ONE 2009;4:e5195.
Evers 1987 {published data only}
Farmer 2009 {published data only}
  • Farmer AJ, Wade AN, French DP, Simon J, Yudkin P, Gray A, et al. Blood glucose self-monitoring in type 2 diabetes: a randomised controlled trial. Health Technology Assessment 2009;13:iii-iv, ix-xi, 1-50.
Fehily 1991 {published data only}
  • Fehily AM, Vaughan-Williams E, Shiels K, Williams AH, Horner M, Bingham G. Factors influencing compliance with dietary advice: the Diet and Reinfarction Trial (DART). Journal of Human Nutrition and Dietetics 1991:33-42.
Ferrante 2010 {published data only}
  • Ferrante D, Varini S, Macchia A, Soifer S, Badra R, Nul D, et al. Long-term results after a telephone intervention in chronic heart failure: DIAL (Randomized Trial of Phone Intervention in Chronic Heart Failure) follow-up. Journal of the American College of Cardiology 2010;56:372-8.
Fitzgibbon 2005 {published data only}
  • Fitzgibbon ML, Stolley MR, Schiffer L, Sanchez-Johnsen LA, Wells AM, Dyer A. A combined breast health/weight loss intervention for Black women. Preventive Medicine 2005;40:373-83.
Forget 1990 {published data only}
  • Forget D, Caranhac G, Quillot MJ, Besnier MO. Compliance with very low protein diet and ketoanalogues in chronic renal failure. The French Multicentric Trial IRCCA. Contributions to Nephrology 1990;81:79-86.
Forli 2001 {published data only}
Forrester 2010 {published data only}
  • Forrester DL, Britton J, Lewis SA, Pogson Z, Antoniak M, Pacey SJ, et al. Impact of adopting low sodium diet on biomarkers of inflammation and coagulation: a randomised controlled trial. Journal of Nephrology 2010;23:49-54.
Fox 1996 {published data only}
  • Fox AA, Thompson JL, Butterfield GE, Gylfadottir U, Moynihan S, Spiller G. Effects of diet and exercise on common cardiovascular disease risk factors in moderately obese older women. The American Journal of Clinical Nutrition 1996;63:225-33.
Frohling 1990 {published data only}
Frost 2007 {published data only}
Fuchs 1993 {published data only}
  • Fuchs Z, Viskoper JR, Drexler I, Nitzan H, Lubin F, Berlin S, et al. Comprehensive individualised nonpharmacological treatment programme for hypertension in physician-nurse clinics: two year follow-up. Journal of Human Hypertension 1993;7:585-91.
Glasgow 2003 {published data only}
  • Glasgow RE, Boles SM, McKay HG, Feil EG, Barrera M Jr. The D-Net diabetes self-management program: long-term implementation, outcomes, and generalization results. Preventive Medicine 2003;36:410-9.
Gorin 2010 {published and unpublished data}
  • Gorin A, Raynor H, Fava J, Maguire K, Robichaud E, Trautvetter J, Crane M, Wing RR. Randomized control trial of a comprehensive home environment-focused weight loss program for adults: 18 month results. Obesity Society Annual Scientific Meeting. 2010:95-OR.
  • Gorin AA, Raynor HA, Fava J, Maguire K, Robichaud E, Trautvetter J, et al. Randomised controlled trial of a comprehensive home environment-focused weight loss program for adults. Health Psychology 2012;Feb 6:E pub ahead of print. [DOI: 10.1037/a0026959]
Grancelli 2003 {published data only}
  • Grancelli H, Varini S, Ferrante D, Schwartzman R, Zambrano C, Soifer S, et al. Randomized Trial of Telephone Intervention in Chronic Heart Failure (DIAL): study design and preliminary observations. Journal of Cardiac Failure 2003;9:172-9.
Greene 1977 {published data only}
Hakala 1993 {published data only}
  • Hakala P, Karvetti RL, Ronnemaa T. Group vs. individual weight reduction programmes in the treatment of severe obesity: a five year follow-up study. International Journal of Obesity 1993;17:97-102.
Hartwell 1986 {published data only}
Harvey-Berino 2004 {published data only}
Harvey-Berino 2009 {published data only}
  • Harvey Berino J, West D, Krukowski R, Prewitt E, VanBiervliet A, Ashikaga T, et al. Internet delivered behavioral obesity treatment. Preventive Medicine 2010;51(2):123-8.
  • Harvey-Berino J, West D, Prewitt TE, VanBiervliet A, Ashikaga T. Internet delivered behavioral obesity treatment. Obesity Research 2009;17:S77.
Hebert 2001 {published data only}
  • Hebert JR, Ebbeling CB, Olendzki BC, Hurley TG, Ma Y, Saal N, et al. Change in women's diet and body mass following intensive intervention for early-stage breast cancer. Journal of the American Dietetic Association 2001;101:421-31.
Henkin 2000 {published data only}
  • Henkin Y, Shai I, Zuk R, Brickner D, Zuilli I, Neumann L, et al. Dietary treatment of hypercholesterolemia: do dietitians do it better? A randomized, controlled trial. American Journal of Medicine 2000;109:549-55.
Heraief 1985 {published data only}
  • Heraief E, Burckhardt P, Wurtman JJ, Wurtman RJ. Tryptophan administration may enhance weight loss by some moderately obese patients on a protein-sparing modified fast (PSMF) diet. International Journal of Eating Disorders 1985:281-92.
Hyman 1998 {published data only}
Jolly 1998 {published data only}
  • Jolly K, Bradley F, Sharp S, Smith H, Mant D. Follow-up care in general practice of patients with myocardial infarction or angina pectoris: initial results of the SHIP trial. Southampton Heart Integrated Care Project. Family Practice 1998;15:548-55.
Jolly 2007 {published data only}
  • Jolly K, Taylor R, Lip GY, Greenfield S, Raftery J, Mant J, et al. The Birmingham Rehabilitation Uptake Maximisation Study (BRUM). Home-based compared with hospital-based cardiac rehabilitation in a multi-ethnic population: cost-effectiveness and patient adherence. Health Technology Assessment 2007;11:1-118.
Jones 2003 {published data only}
  • Jones H, Edwards L, Vallis TM, Ruggiero L, Rossi SR, Rossi JS, et al. Changes in diabetes self-care behaviors make a difference in glycemic control: the Diabetes Stages of Change (DiSC) study. Diabetes Care 2003:732-7.
Jula 1990 {published data only}
Kaiman 2000 {published data only}
  • Kaiman DS, Colker CM, Swain MA, Torina GC, Shi Q. A randomized, double-blind, placebo-controlled study of 3-acetyl-7-oxo-dehydroepiandrosterone in healthy overweight adults. Current Therapeutic Research 2000;61:435-42.
Kalodner 1991 {published data only}
  • Kalodner CR, DeLucia JL. The individual and combined effects of cognitive therapy and nutrition education as additions to a behavior modification program for weight loss. Addictive Behaviors 1991;16:255-63.
Kalter-Leibovici 2010 {published data only}
  • Kalter-Leibovici O, Younis-Zeidan N, Atamna A, Lubin F, Alpert G, Chetrit A, et al. Lifestyle intervention in obese Arab women: a randomized controlled trial. Archives of Internal Medicine 2010;170:970-6.
Kattelmann 2009 {published data only}
  • Kattelmann KK, Conti K, Ren C. The medicine wheel nutrition intervention: a diabetes education study with the Cheyenne River Sioux Tribe. Journal of the American Dietetic Association 2009;109:1532-9.
Khoo 2007 {published data only}
  • Khoo CK, Vickery CJ, Forsyth N, Vinall NS, Eyre-Brook IA. A prospective randomized controlled trial of multimodal perioperative management protocol in patients undergoing elective colorectal resection for cancer. Annals of Surgery 2007;245:867-72.
Kim 2006 {published data only}
  • Kim SH, Lee SJ, Kang ES, Kang S, Hur KY, Lee HJ, et al. Effects of lifestyle modification on metabolic parameters and carotid intima-media thickness in patients with type 2 diabetes mellitus. Metabolism Clinical and Experimental 2006;55:1053-9.
Kirkman 1994 {published data only}
  • Kirkman MS, Weinberger M, Landsman PB, Samsa GP, Shortliffe EA, Simel DL, et al. A telephone-delivered intervention for patients with NIDDM. Effect on coronary risk factors. Diabetes Care 1994;17:840-6.
Koelewijn-van Loon 2009 {published and unpublished data}
  • Koelewijn-van Loon MS, van der Weijden T, van Steenkiste B, Ronda G, Winkens B, Severens JL, et al. Involving patients in cardiovascular risk management with nurse-led clinics: a cluster randomized controlled trial. Canadian Medical Association Journal 2009;181:E267-74.
Korhonen 1983 {published data only}
  • Korhonen T, Huttunen JK, Aro A, Hentinen M, Ihalainen O, Majander H, et al. A controlled trial on the effects of patient education in the treatment of insulin-dependent diabetes. Diabetes Care 1983;6:256-61.
Korhonen 2003 {published data only}
  • Korhonen M, Kastarinen M, Uusitupa M, Puska P, Nissinen A. The effect of intensified diet counseling on the diet of hypertensive subjects in primary health care: a 2-year open randomized controlled trial of lifestyle intervention against hypertension in eastern Finland. Preventive Medicine 2003;36:8-16.
Krier 1999 {published data only}
  • Krier BP, Parker RD, Grayson D, Byrd G. Effect of diabetes education on glucose control. Journal of the Louisiana State Medical Society 1999;151:86-92.
Kumanyika 1993 {published data only}
  • Kumanyika SK, Hebert PR, Cutler JA, Lasser VI, Sugars CP, Steffen-Batey L, et al. Feasibility and efficacy of sodium reduction in the Trials of Hypertension Prevention, phase I. Trials of Hypertension Prevention Collaborative Research Group. Hypertension 1993;22:502-12.
Lampman 1977 {published data only}
  • Lampman RM, Santinga JT, Hodge MF, Block WD, Flora JD Jr, Bassett DR. Comparative effects of physical training and diet in normalizing serum lipids in men with Type IV hyperlipoproteinemia. Circulation 1977;55:652-9.
Laws 2004 {published data only}
Leermakers 1999 {published data only}
  • Leermakers EA, Perri MG, Shigaki CL, Fuller PR. Effects of exercise-focused versus weight-focused maintenance programs on the management of obesity. Addictive Behaviors 1999;24:219-27.
Lesley 2007 {published data only}
  • Lesley M L. Social problem solving training for African Americans: effects on dietary problem solving skill and DASH diet-related behavior change. Patient Education and Counseling 2007;65:137-46.
Lindahl 2009 {published data only}
  • Lindahl B, Nilssön TK, Borch-Johnsen K, Røder ME, Söderberg S, Widman L, et al. A randomized lifestyle intervention with 5-year follow-up in subjects with impaired glucose tolerance: pronounced short-term impact but long-term adherence problems: erratum. Scandinavian Journal of Public Health 2009;37:443.
Locatelli 1990 {published data only}
Lopez 2006 {published data only}
  • Lopez Cabezas C, Falces Salvador C, Cubi Quadrada D, Arnau Bartes A, Ylla Bore M, Muro Perea N, et al. Randomized clinical trial of a postdischarge pharmaceutical care program vs regular follow-up in patients with heart failure. Farmacia Hospitalaria 2006;30:328-42.
Manchanda 2000 {published data only}
  • Manchanda SC, Narang R, Reddy KS, Sachdeva U, Prabhakaran D, Dharmanand S, et al. Retardation of coronary atherosclerosis with yoga lifestyle intervention. Journal of Association of Physicians of India 2000;48:687-94.
Mathus-Vliegen 1993 {published data only}
  • Mathus-Vliegen LM, Res AM. Dexfenfluramine influences dietary compliance and eating behavior, but dietary instruction may overrule its effect on food selection in obese subjects. Journal of American Dietetic Association 1993;93:1163-5.
McCarron 1998 {published data only}
  • McCarron DA, Oparil S, Resnick LM, Chait A, Haynes RB, Kris-Etherton P, et al. Comprehensive nutrition plan improves cardiovascular risk factors in essential hypertension. American Journal of Hypertension 1998;11:31-40.
McConnon 2007 {published data only}
  • McConnon A, Kirk SF, Cockroft JE, Harvey EL, Greenwood DC, Thomas JD, et al. The Internet for weight control in an obese sample: results of a randomised controlled trial. BMC Health Services Research 2007;7:206.
McConnon 2009 {published data only}
  • McConnon A, Kirk SF, Ransley JK. Process evaluation of an internet-based resource for weight control: use and views of an obese sample. Journal of Nutrition Education and Behavior 2009;41:261-7.
Melchionda 2006 {published data only}
  • Melchionda N, Forlani G, La Rovere L, Argnani P, Trevisani F, Zocchi D, et al. Disease management of the metabolic syndrome in a community: study design and process analysis on baseline data. Metabolic Syndrome and Related Disorders 2006; Vol. 4, issue 1:7-16.
Melin 2003 {published data only}
  • Melin I, Karlstrom B, Lappalainen R, Berglund L, Mohsen R, Vessby B. A programme of behaviour modification and nutrition counselling in the treatment of obesity: a randomised 2-y clinical trial. International Journal of Obesity 2003;27:1127-35.
Metz 1997 {published data only}
  • Metz JA, Kris-Etherton PM, Morris CD, Mustad VA, Stern JS, Oparil S, et al. Dietary compliance and cardiovascular risk reduction with a prepared meal plan compared with a self-selected diet. American Journal of Clinical Nutrition 1997;66:373-85.
Metz 2000 {published data only}
  • Metz JA, Stern JS, Kris-Etherton P, Reusser ME, Morris CD, Hatton DC, et al. A randomized trial of improved weight loss with a prepared meal plan in overweight and obese patients: impact on cardiovascular risk reduction. Archives of Internal Medicine 2000;160:2150-8.
Mhurchu 1998 {published data only}
  • Mhurchu CN, Margetts BM, Speller V. Randomized clinical trial comparing the effectiveness of two dietary interventions for patients with hyperlipidaemia. Clinical Science 1998;95:479-87.
Milas 1995 {published data only}
  • Milas NC, Nowalk MP, Akpele L, Castaldo L, Coyne T, Doroshenko L, et al. Factors associated with adherence to the dietary protein intervention in the Modification of Diet in Renal Disease Study. Journal of the American Dietetic Association 1995;95:1295-300.
Miller 2009 {published data only}
  • Miller CK, Gutshcall MD, Mitchell DC. Change in food choices following a glycemic load intervention in adults with type 2 diabetes. Journal of the American Dietetic Association 2009;109:319-24.
Morgan 2009 {published data only}
Nir 2004 {published data only}
  • Nir Z, Zolotogorsky Z, Sugarman H. Structured nursing intervention versus routine rehabilitation after stroke. American Journal of Physical Medicine and Rehabilitation 2004;83:522-9.
Nugent 1984 {published data only}
Oldroyd 2006 {published data only}
  • Oldroyd JC, Unwin NC, White M, Mathers JC, Alberti KG. Randomised controlled trial evaluating lifestyle interventions in people with impaired glucose tolerance. Diabetes Research and Clinical Practice 2006;72:117-27.
Ornish 1998 {published data only}
  • Ornish D, Scherwitz LW, Billings JH, Brown SE, Gould KL, Merritt TA, et al. Intensive lifestyle changes for reversal of coronary heart disease. Journal of the American Medical Association 1998;280:2001-7.
Pater 2000 {published data only}
  • Pater C, Ditlef Jacobsen C, Rollag A, Sandvik L, Erikssen J, Karin Kogstad E. Design of a randomized controlled trial of comprehensive rehabilitation in patients with myocardial infarction, stabilized acute coronary syndrome, percutaneous transluminal coronary angioplasty or coronary artery bypass grafting: Akershus Comprehensive Cardiac Rehabilitation Trial (the CORE Study). Current Controlled Trials in Cardiovascular Medicine 2000;1:177-83.
Pettman 2008 {published data only}
  • Pettman TL, Misan GM, Owen K, Warren K, Coates AM, Buckley JD, et al. Self-management for obesity and cardio-metabolic fitness: description and evaluation of the lifestyle modification program of a randomised controlled trial. International Journal of Behavioral Nutrition and Physical Activity 2008;5:53. [DOI: 10.1186/1479-5868-5-53]
Pierce 1997 {published data only}
  • Pierce JP, Faerber S, Wright FA, Newman V, Flatt SW, Kealey S, et al. Feasibility of a randomized trial of a high-vegetable diet to prevent breast cancer recurrence. Nutrition and Cancer 1997;28:282-8.
Pierce 2002 {published data only}
  • Pierce JP, Faerber S, Wright FA, Rock CL, Newman V, Flatt SW, et al. A randomized trial of the effect of a plant-based dietary pattern on additional breast cancer events and survival: the Women's Healthy Eating and Living (WHEL) Study. Controlled Clinical Trials 2002;23:728-56.
Pierce 2007 {published data only}
  • Pierce JP, Newman VA, Natarajan L, Flatt SW, Al-Delaimy WK, Caan BJ, et al. Telephone counseling helps maintain long-term adherence to a high-vegetable dietary pattern. The Journal of Nutrition 2007;137:2291-6.
Pijls 2000 {published data only}
  • Pijls LT, de Vries H, van Eijk JT, Donker AJ. Adherence to protein restriction in patients with type 2 diabetes mellitus: a randomized trial. European Journal of Clinical Nutrition 2000;54:347-52.
Pringle 1993 {published data only}
Rabkin 1983 {published data only}
  • Rabkin SW, Boyko E, Wilson A, Streja DA. A randomized clinical trial comparing behavior modification and individual counseling in the nutritional therapy of non-insulin-dependent diabetes mellitus: comparison of the effect on blood sugar, body weight, and serum lipids. Diabetes Care 1983;6:50-6.
Racette 1995 {published data only}
  • Racette SB, Schoeller DA, Kushner RF, Neil KM. Exercise enhances dietary compliance during moderate energy restriction in obese women. The American Journal of Clinical Nutrition 1995;62:345-9.
Rallidis 2009 {published data only}
  • Rallidis LS, Lekakis J, Kolomvotsou A, Zampelas A, Vamvakou G, Efstathiou S, et al. Close adherence to a Mediterranean diet improves endothelial function in subjects with abdominal obesity. The American Journal of Clinical Nutrition 2009;90:263-8.
Rhew 2007 {published data only}
  • Rhew I, Yasui Y, Sorensen B, Ulrich CM, Neuhouser ML, Tworoger SS, et al. Effects of an exercise intervention on other health behaviors in overweight/obese post-menopausal women. Contemporary Clinical Trials 2007;28:472-81.
Rimmer 2000 {published data only}
  • Rimmer JH, Braunschweig C, Silverman K, Riley B, Creviston T, Nicola T. Effects of a short-term health promotion intervention for a predominantly African-American group of stroke survivors. American Journal of Preventive Medicine 2000;18:332-8.
Robertson 1992 {published data only}
  • Robertson I, Phillips A, Mant D, Thorogood M, Fowler G, Fuller A, et al. Motivational effect of cholesterol measurement in general practice health checks. British Journal of General Practice 1992;42:469-72.
Rosman 1989 {published data only}
  • Rosman JB, Langer K, Brandl M, Piers-Becht TP, van der Hem GK, ter Wee PM, et al. Protein-restricted diets in chronic renal failure: a four year follow-up shows limited indications. Kidney International 1989;27:S96-102.
Rosman 1990 {published data only}
Roumen 2008 {published data only}
Sadur 1999 {published data only}
  • Sadur CN, Moline N, Costa M, Michalik D, Mendlowitz D, Roller S, et al. Diabetes management in a health maintenance organization. Efficacy of care management using cluster visits. Diabetes Care 1999;22:2011-7.
Sartorio 2003 {published data only}
  • Sartorio A, Lafortuna CL, Marinone PG, Tavani A, La Vecchia C, Bosetti C. Short-term effects of two integrated, non-pharmacological body weight reduction programs on coronary heart disease risk factors in young obese patients. Diabetes, Nutrition & Metabolism 2003;16:262-5.
Schapira 1991 {published data only}
  • Schapira DV, Kumar NB, Lyman GH, Baile WF. The effect of duration of intervention and locus of control on dietary change. American Journal of Preventive Medicine 1991;7:341-7.
Sevick 2008 {published and unpublished data}
  • Sevick MA, Zickmund S, Korytkowski M, Piraino B, Sereika S, Mihalko S, et al. Design, feasibility, and acceptability of an intervention using personal digital assistant-based self-monitoring in managing type 2 diabetes. Contemporary Clinical Trials 2008;29:396-409.
Shaw-Stuart 2000 {published data only}
  • Shaw-Stuart NJ, Stuart A. The effect of an educational patient compliance program on serum phosphate levels in patients receiving hemodialysis. Journal of Renal Nutrition 2000;10:80-4.
Singh 1991 {published data only}
  • Singh RB, Rastogi SS, Sircar AR, Mehta PJ, Sharma KK. Dietary strategies for risk-factor modification to prevent cardiovascular diseases. Nutrition 1991;7:210-4.
Singh 1992 {published data only}
Sisk 2006 {published data only}
  • Sisk JE, Hebert PL, Horowitz CR, McLaughlin MA, Wang JJ, Chassin MR. Effects of nurse management on the quality of heart failure care in minority communities: a randomized trial. Annals of Internal Medicine 2006;145:273-83.
Smith 1997 {published data only}
  • Smith DE, Heckemeyer CM, Kratt PP, Mason DA. Motivational interviewing to improve adherence to a behavioral weight-control program for older obese women with NIDDM. A pilot study. Diabetes Care 1997;20:52-4.
Sone 2010 {published data only}
  • Sone H, Tanaka S, Iimuro S, Oida K, Yamasaki Y, Oikawa S, et al. Long-term lifestyle intervention lowers the incidence of stroke in Japanese patients with type 2 diabetes: a nationwide multicentre randomised controlled trial (the Japan Diabetes Complications Study). Diabetologia 2010;53:419-28.
Southard 2003 {published data only}
  • Southard BH, Southard DR, Nuckolls J. Clinical trial of an Internet-based case management system for secondary prevention of heart disease. Journal of Cardiopulmonary Rehabilitation 2003;23:341-8.
Sperduto 1986 {published data only}
  • Sperduto WA, Thompson HS, O'Brien RM. The effect of target behavior monitoring on weight loss and completion rate in a behavior modification program for weight reduction. Addictive Behaviors 1986:337-40.
Thoolen 2009 {published data only}
  • Thoolen BJ, de Ridder D, Bensing J, Gorter K, Rutten G. Beyond good intentions: The role of proactive coping in achieving sustained behavioural change in the context of diabetes management. Psychology and Health 2009;24:237-54.
Tilley 1997 {published data only}
  • Tilley BC, Vernon SW, Glanz K, Myers R, Sanders K, Lu M, et al. Worksite cancer screening and nutrition intervention for high-risk auto workers: design and baseline findings of the Next Step Trial. Preventive Medicine 1997;26:227-35.
Toobert 1998 {published data only}
  • Toobert DJ, Glasgow RE, Nettekoven LA, Brown JE. Behavioral and psychosocial effects of intensive lifestyle management for women with coronary heart disease. Patient Education and Counseling 1998;35:177-88.
Toobert 2000 {published data only}
Torgerson 1999 {published data only}
  • Torgerson JS, Agren L, Sjostrom L. Effects on body weight of strict or liberal adherence to an initial period of VLCD treatment. A randomised, one-year clinical trial of obese subjects. International Journal of Obesity 1999;23:190-7.
Tsang 2001 {published data only}
  • Tsang MW, Mok M, Kam G, Jung M, Tang A, Chan U, et al. Improvement in diabetes control with a monitoring system based on a hand-held, touch-screen electronic diary. Journal of Telemedicine and Telecare 2001;7:47-50.
Vale 2003 {published and unpublished data}
  • Vale MJ, Jelinek MV, Best JD, Dart AM, Grigg LE, Hare DL, et al. Coaching patients On Achieving Cardiovascular Health (COACH): a multicenter randomized trial in patients with coronary heart disease. Archives of Internal Medicine 2003;163:2775-83.
van der Weijden 1998 {published data only}
  • van der Weijden T, Grol RPTM, Schouten BJ, Knottnerus JA. Barriers to working according to cholesterol guidelines: A randomized controlled trial on implementation of national guidelines in 20 general practices. European Journal of Public Health 1998;8(2):113-8.
van Gool 2006 {published data only}
  • van Gool CH, Penninx BW, Kempen GI, Miller GD, van Eijk JT, Pahor M, et al. Determinants of high and low attendance to diet and exercise interventions among overweight and obese older adults. Results from the arthritis, diet, and activity promotion trial. Contemporary Clinical Trials 2006;27:227-37.
Verges 1998 {published data only}
  • Verges BL, Patois-Verges B, Cohen M, Casillas JM. Comprehensive cardiac rehabilitation improves the control of dyslipidemia in secondary prevention. European Journal of Public Health 1998;18:408-15.
Voils 2009 {published data only}
  • Voils CI, Yancy WS Jr, Kovac S, Coffman CJ, Weinberger M, Oddone EZ, et al. Study protocol: Couples Partnering for Lipid Enhancing Strategies (CouPLES) - a randomized, controlled trial. Trials 2009;10:10.
von Gruenigen 2008 {published data only}
  • von Gruenigen VE, Courneya KS, Gibbons HE, Kavanagh MB, Waggoner SE, Lerner E. Feasibility and effectiveness of a lifestyle intervention program in obese endometrial cancer patients: a randomized trial. Gynecologic Oncology 2008;109:19-26.
Wadden 1997 {published data only}
Wadden 2009 {published data only}
Webber 2010 {published data only}
  • Webber KH, Tate DF, Ward DS, Bowling JM. Motivation and its relationship to adherence to self-monitoring and weight loss in a 16-week Internet behavioral weight loss intervention. Journal of Nutrition Education and Behavior 2010;42:161-7.
Wing 1986 {published data only}
  • Wing RR, Epstein LH, Nowalk MP, Scott N, Koeske R, Hagg S. Does self-monitoring of blood glucose levels improve dietary compliance for obese patients with type II diabetes?. The American Journal of Medicine 1986;81:830-6.
Wing 1996 {published data only}
  • Wing RR, Jeffery RW, Hellerstedt WL, Burton LR. Effect of frequent phone contacts and optional food provision on maintenance of weight loss. Annals of Behavioral Medicine 1996;18:172-6.
Wing 1999 {published data only}
Wing 2003 {published data only}
Witmer 2004 {published data only}
  • Witmer JM, Hensel MR, Holck PS, Ammerman AS, Will JC. Heart disease prevention for Alaska Native women: a review of pilot study findings. Journal of Women's Health 2004;13:569-78.
Wright 1981 {published data only}
Zismer 1982 {published data only}

References to studies awaiting assessment

  1. Top of page
  2. AbstractRésumé scientifique
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Characteristics of studies
  17. References to studies included in this review
  18. References to studies excluded from this review
  19. References to studies awaiting assessment
  20. References to ongoing studies
  21. Additional references
  22. References to other published versions of this review
Aldous 2009 {published data only}
  • Aldous D, Firth W. Impact of a nutrition intervention with applied motivational interviewing and behavior change techniques in the Community Cardiovascular Hearts in Motion (CCHIM) program-preliminary findings. Canadian Foundation for Dietetic Research; Showcase of Dietetic Research in Canada. 2009:18.
Amato 1990 {published data only}
  • Amato S, Colajanni E, Averna MR, Barbagallo CM, Lo Cascio ML, Traina G, et al. [Diet and psychological therapy in a group of severely obese patients]. Minerva Endocrinologica 1990;15:219-21.
Clark 2004 {published data only}
Contel 1993 {published data only}
  • Contel JC, Adell A, Álvarez S, Baulies T, Campamà I, Gómez I, et al. Food-meter glass: usefulness to promote the compliance with the diet in primary care consultations. Annals de Medicina 1993:212.
Duncan 2001 {published data only}
  • Duncan K, Pozehl B, Rosado K. The effects of behavioral feedback on adherence to dietary sodium intake for patients with congestive heart failure. Journal of Cardiopulmonary Rehabilitation 2001:304.
Fernández López 2007 {published data only}
  • Fernández López L, Guerrero Llamas L, Gutiérrez Villaplana JM, Estrada Reventos D, Casal Garcia MC, Andugar Hernández J, et al. Mixed intervention programme on compliance and quality of life in hypertensive patients [Spanish]. Revista de la Sociedad Española de Enfermería Nefrológica 2007;10:7-13.
Firth 2009 {published data only}
  • Firth W, Pancura B. Can a web-based, self-monitoring wellness program augment outcomes and lead to sustained weight management and exercise ability at one year after completing a community cardiac rehabilitation program?. Canadian Foundation for Dietetic Research; Showcase of Dietetic Research in Canada. 2004:19.
González 1987 {published data only}
  • González CA, Forés D, Avilés A, Argimón JM, Boada JM, Cubí R, et al. Efficacy of a self-control method for the compliance with low-salt diet. Atención Primaria 1987:258-62.
Hauner 2006 {published data only}
  • Hauner H. An intense nutritional training program for obese patients with type 2 diabetes mellitus: a randomised controlled two-year intervention study. Current Controlled Trials 2006.
Kim 2003 {published data only}
Koprucki 2010 {published and unpublished data}
  • Koprucki M, Piraino B, Bender F, Snetselaar L, Hall B, Stark S, et al. RCT of Personal Digital Assistant (PDA) supported dietary intervention to reduce sodium intake in PD. American Journal of Kidney Diseases 2010;55:A72.
Lin 2007 {published data only}
  • Lin PH, Appel LJ, Funk K, Craddick S, Chen C, Elmer P, et al. The PREMIER intervention helps participants follow the Dietary Approaches to Stop Hypertension dietary pattern and the current Dietary Reference Intakes recommendations. Obesity 2007;107:1541-51.
Martínez-Marcos 1999 {published data only}
  • Martínez Marcos M, Domínguez Bidagor J, Sempere Jorda R, Benito MJ, Rodríguez Martín R, Rapp Fernández P, et al. Evaluation of a nursing intervention for improving self-care of patients with diabetes [Spanish]. Metas de Enfermería 1999;2:45-51.
Mayeux 2004 {published data only}
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Mensink 2003 {published data only}
Paisey 2005 {published and unpublished data}
  • Paisey R. Group education randomisation trial of type II diabetes practice care or continued group education. Current Controlled Trials 2005.
Simpson 2010 {published and unpublished data}
  • Simpson S. A randomised controlled trial of a 12-month multi-component intervention versus a less intensive version on study participants' maintenance of weight loss. Current Controlled Trials 2010.
Song 2009 {published data only}
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Stollar 1993 {published data only}
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Wedman 1987 {published data only}

References to ongoing studies

  1. Top of page
  2. AbstractRésumé scientifique
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Characteristics of studies
  17. References to studies included in this review
  18. References to studies excluded from this review
  19. References to studies awaiting assessment
  20. References to ongoing studies
  21. Additional references
  22. References to other published versions of this review
Feldman 2009 {published and unpublished data}
  • Feldman PH, McDonald MV, Mongoven JM, Peng TR, Gerber LM, Pezzin LE. Home-based blood pressure interventions for blacks. Circulation Cardiovascular Quality and Outcomes 2009;2:241-8.
Griva 2010 {published and unpublished data}
  • Griva K. The effectiveness of a self-management intervention to improve outcomes in prevalent haemodialysis patients: a randomised controlled trial. Current Controlled Trials 2010.
Jansink 2006 {published and unpublished data}
  • Jansink R, Braspenning J, van der Weijden T, Niessen L, Elwyn G, Grol R. Nurse-led motivational interviewing to change the lifestyle of patients with type 2 diabetes (MILD-project): protocol for a cluster, randomized, controlled trial on implementing lifestyle recommendations. BMC Health Services Research 2009;9:19.
  • Jansink RME. Motivational interview by practice nurses to improve lifestyle adherence in patients with type 2 diabetes. Current Controlled Trials 2006.
Ma 2009 {published data only}
  • Ma J, King AC, Wilson SR, Xiao L, Stafford RS. Evaluation of lifestyle interventions to treat elevated cardiometabolic risk in primary care (E-LITE): a randomized controlled trial. BMC Family Practice 2009;10:71.
Sher 2002 {published data only}
  • Sher TG, Bellg AJ, Braun L, Domas A, Rosenson R, Canar WJ. Partners for Life: a theoretical approach to developing an intervention for cardiac risk reduction. Health Education Research 2002;17:597-605.

Additional references

  1. Top of page
  2. AbstractRésumé scientifique
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
  16. Characteristics of studies
  17. References to studies included in this review
  18. References to studies excluded from this review
  19. References to studies awaiting assessment
  20. References to ongoing studies
  21. Additional references
  22. References to other published versions of this review
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