Prevention of relapse after quitting smoking: a systematic review of trials.
BACKGROUND: After initially successful quit attempts, many people return to smoking within a year, reducing the public health benefits of investment in smoking cessation. We aimed to assess whether interventions designed to prevent relapse after a successful quit attempt reduce the proportion of recent quitters who return to smoking. METHODS: We searched the Cochrane Tobacco Addiction Review Group trials' register. We selected randomized or quasi-randomized controlled trials of relapse prevention interventions with a minimum follow-up of 6 months. We included people who quit on their own, underwent enforced abstinence, or were in treatment programs. We included trials comparing relapse prevention interventions with no intervention or cessation plus relapse prevention with cessation intervention alone. Two of us independently extracted data from each report, with disagreements referred to a third author. RESULTS: Forty-two studies met the inclusion criteria. The most common interventions were skills training to identify and resolve tempting situations and extended treatment contact. A few studies tested pharmacotherapy. We separately analyzed studies that randomized abstainers and those that randomized participants before their quit date. Within subgroups of trials, pooled odds ratios ranged from 0.86 to 1.30, and in most analyses, 95% confidence intervals included 1. Most studies had limited power to detect moderate differences between interventions. CONCLUSION: The evidence to date does not support the adoption of skills training or other specific interventions to help individuals who have successfully quit smoking to avoid relapse, but this is an important area for future study.