|Behavioural interventions for smoking cessation: a meta-analysis of randomized controlled trials
|Mottillo S, Filion KB, Belisle P, Joseph L, Gervais A, O'Loughlin J, Paradis G, Pihl R, Pilote L, Rinfret S, Tremblay M, Eisenberg MJ
This review concluded that intensive behavioural interventions, including individual, group, and telephone counselling, significantly increased smoking abstinence in people motivated to stop smoking. Conclusions could not be drawn regarding minimal clinical intervention. The authors' conclusions appear to reflect the evidence, but given limitations with the review process and the quality of the included studies, they should be interpreted with caution.
To assess the efficacy of behavioural interventions for smoking cessation.
EMBASE, MEDLINE, PsycINFO, the Cochrane Library, and the CDC Tobacco Information and Prevention databases were searched up to August 2007 for articles published in English. Search terms were reported. In addition, reference lists of relevant articles were also searched.
Randomised controlled trials (RCTs) of smoking cessation behavioural interventions that compared usual care plus minimal clinical intervention (single consultation lasting a maximum of 20 minutes), individual, group, or telephone counselling (as defined by the Cochrane Collaboration) with usual care alone, were eligible for inclusion. RCTs specifying that patients were not motivated were excluded. Usual care consisted of self-help materials, with or without advice on stopping smoking, or no treatment. Only RCTs reporting biochemically validated point prevalence (defined as no smoking over a time period, usually seven days, directly preceding follow-up) and continuous smoking abstinence at six and 12 months were eligible. Cluster RCTs randomised by therapist or centre rather than at the patient level, were excluded.
Included trials were of healthy patients or ‘at risk’ patients (eg. pregnant women or patients with diabetes), smoking a mean of between 20 and 30 cigarettes per day (where reported). The majority of trials were conducted in the USA or UK, in single or multiple centres. Where reported, treatments ranged between two and 12 sessions lasting a total of between three minutes and 16 hours, spanning between one and 36 weeks (where reported). Delivery agents varied across trials. Some of the included trials used multi-component counselling sessions (e.g. individual counselling and telephone counselling) and/or pharmacotherapy (e.g. nicotine patches). Control groups in some trials received brief advice from a healthcare intervention.
The authors did not state how many reviewers screened articles for relevance, or how discrepancies were resolved.
Assessment of study quality
Included trials were assessed on quality using a modified Jadad scale for criteria on randomisation and patient withdrawals/drop-outs. The maximum score was 3 points, with 3 denoting low probability of bias.
The authors did not state how many reviewers assessed quality of the studies.
Two reviewers independently extracted outcome data on an intention-to-treat basis to calculate odds ratios and 95% credible intervals (Crls). Disagreements were resolved through discussion with a third reviewer.
Methods of synthesis
A Bayesian hierarchical random-effects model was used to combine odds ratios and 95% credible intervals by intervention type. For RCTs with multiple arms, the control group was re-used in each comparison, but was accounted for within the analysis to avoid double counting. The prior distributions used within the model were described within the text. Publication bias was assessed using funnel plots.
Results of the review
Fifty RCTs, including 64 comparisons (n=26,927 participants), were included in the review. Sample sizes ranged between 29 and 3,102 participants. The average quality score was 2.14, indicating that the majority of RCTs had medium to low probability of bias.
The minimal clinical intervention was not statistically significantly effective in reducing smoking (nine RCTs), but the remaining three interventions did significantly increase smoking abstinence compared with control groups: individual counselling (OR 1.49, 95% Crl 1.08 to 2.07, 23 RCTs), group counselling (OR 1.76, 95% Crl 1.11 to 2.93, 12 RCTs), and telephone counselling (OR 1.58 to 95% Crl 1.15, 2.29, 10 RCTs).
Intensive behavioural interventions, including individual, group, and telephone counselling, significantly increased smoking abstinence in people motivated to stop smoking. Minimal clinical intervention may increase smoking cessation, but the evidence was insufficient to draw firm conclusions regarding its efficacy.
The review question was supported by clear inclusion criteria. Several appropriate databases were searched, but this was limited to publications in English, so language bias may have been introduced. There was no apparent search for unpublished papers, so other potentially relevant papers may have been missed. Publication bias was reported to have been assessed, but the results were not reported. The quality of trials was assessed using reliable measurement tools. The mean quality score across all included RCTs suggested that the overall quality was medium to high, but quality scores for individual RCTs were not provided, which made it difficult to assess the accuracy of the results for each intervention type. The authors undertook data extraction in duplicate, but did not state whether similar steps were taken for study selection and validity assessment, so reviewer error and bias cannot be ruled out. A random-effects model was used in an attempt to account for potential heterogeneity. The authors acknowledged certain limitations with the included trials, such as clinical and methodological heterogeneity, and wide credible intervals for each intervention.
The authors' conclusions appear to reflect the evidence, but given limitations with the potential for review bias and the quality of the included studies, they should be interpreted with caution.
Implications of the review for practice and research
Practice: The authors stated that healthcare workers should advise smokers to use more intensive individual, group, or telephone counselling for smoking cessation.
Research: The authors did not state any implications for further research.
The Canadian Institutes of Health Research (CIHR grant number 81257); Canadian Cardiovascular Outcomes Research Team grant.
Mottillo S, Filion KB, Belisle P, Joseph L, Gervais A, O'Loughlin J, Paradis G, Pihl R, Pilote L, Rinfret S, Tremblay M, Eisenberg MJ. Behavioural interventions for smoking cessation: a meta-analysis of randomized controlled trials. European Heart Journal 2009; 30(6): 718-730
Other publications of related interest
Stead LF, Bergson G, Lancaster T. Physician advice for smoking cessation. Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD000165. DOI: 10.1002/14651858.CD000165.pub3.
Lancaster T, Stead LF. Individual behavioural counselling for smoking cessation. Cochrane Database of Systematic Reviews 2005, Issue 2. Art. No.: CD001292. DOI: 10.1002/14651858.CD001292.pub2.
Rice VH, Stead LF. Nursing interventions for smoking cessation. Cochrane Database of Systematic Reviews 2008, Issue 1. Art. No.: CD001188. DOI: 10.1002/14651858.CD001188.pub3.
Stead LF, Lancaster T. Group behaviour therapy programmes for smoking cessation. Cochrane Database of Systematic Reviews 2005, Issue 2. Art. No.: CD001007. DOI: 10.1002/14651858.CD001007.pub2.
Stead LF, Perera R, Lancaster T. Telephone counselling for smoking cessation. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD002850. DOI: 10.1002/14651858.CD002850.pub2.
Subject indexing assigned by NLM
Behavior Therapy /methods; Female; Humans; Male; Randomized Controlled Trials as Topic; Smoking /prevention & control; Smoking Cessation /statistics & numerical data; United States
Database entry date
This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.