Efficacy of psychosocial interventions for smoking cessation in patients with coronary heart disease: a systematic review and meta-analysis

BACKGROUND: Quitting smoking improves prognosis after a cardiac event. Therefore smoking cessation is highly recommended for patients with coronary heart disease (CHD), but many patients continue to smoke, and improved cessation aids are urgently required. PURPOSE: The objective was to conduct a systematic review of the efficacy of psychosocial interventions to quit smoking in patients with CHD. METHODS: Seven electronic databases were searched from the start of the database to August 2003. Search terms were coronary or cardio or heart or cvd or chd and smok* and cessation or absti*. Results were supplemented by cross-checking references. More than 2,000 papers were screened in a first step. Eligibility of studies was assessed (by reviewer Jürgen Barth) and reasons for exclusion were coded. Abstinence rates were computed both according to an intention to treat analysis, and based on follow-up results only. RESULTS: We found 19 randomized controlled trials, comparing a specific psychosocial intervention with "usual care," with a minimum of 6-month follow-up. Interventions consist of behavioral therapeutic approaches, telephone support, and self-help material. The trials mostly included older male patients with CHD, predominantly myocardial infarction. Overall results found a positive effect of interventions on abstinence after 6 to 12 months (OR = 1.66, 95% CI = 1.24-2.21), but substantial heterogeneity between trials. Clustering the trials by type of intervention reduced heterogeneity, although many trials used more than one type of intervention. Trials involving behavioral therapies or telephone contact were little different from self-help techniques (OR = 1.65, 95% CI = 1.28-2.13 for behavioral therapies; OR = 1.58, 95% CI = 1.26-1.98 for telephone support; OR = 1.47, 95% CI = 1.10-1.97 for self-help). Treatment intensity was associated with study outcome. More intense interventions showed increased quit rates (OR = 1.95, 95% CI = 1.61-2.35) whereas interventions of low intensity did not appear effective (OR = 0.92, 95% CI = 0.70-1.22). Studies with validated assessment of smoking status at follow-up had lower efficacy than nonvalidated trials. CONCLUSIONS: Smoking cessation interventions are effective in promoting abstinence up to 1 year, provided they are of sufficient intensity with a minimum length of 1 month. Further studies should compare different psychosocial intervention strategies, or the combination of a psychosocial intervention strategy with nicotine replacement therapy or bupropion compared with nicotine replacement or bupropion alone.