Copyright © 2019 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. Background A number of treatments can help smokers make a successful quit attempt, but many initially successful quitters relapse over time. Several interventions have been proposed to help prevent relapse. Objectives To assess whether specific interventions for relapse prevention reduce the proportion of recent quitters who return to smoking. Search methods We searched the Cochrane Tobacco Addiction Group trials register, clinicaltrials.gov, and the ICTRP in February 2018 for studies mentioning relapse prevention or maintenance in their title, abstracts, or keywords. Selection criteria Randomised or quasi-randomised controlled trials of relapse prevention interventions with a minimum follow-up of six months. We included smokers who quit on their own, were undergoing enforced abstinence, or were participating in treatment programmes. We included studies that compared relapse prevention interventionswith a no intervention control, or that compared a cessation programme with additional relapse prevention components with a cessation programme alone. Data collection and analysis We used standard methodological procedures expected by Cochrane. Main results We included 77 studies (67,285 participants), 15 of which are new to this update. We judged 21 studies to be at high risk of bias, 51 to be at unclear risk of bias, and five studies to be at low risk of bias. Forty-eight studies included abstainers, and 29 studies helped people to quit and then tested treatments to prevent relapse. Twenty-six studies focused on special populations who were abstinent because of pregnancy (18 studies), hospital admission (five studies), or military service (three studies). Most studies used behavioural interventions that tried to teach people skills to cope with the urge to smoke, or followed up with additional support. Some studies tested extended pharmacotherapy. We focused on results fromthose studies that randomised abstainers, as these are the best test of relapse prevention interventions. Of the 12 analyses we conducted in abstainers, three pharmacotherapy analyses showed benefits of the intervention: extended varenicline in assisted abstainers (2 studies, n = 1297, risk ratio (RR) 1.23, 95% confidence interval (CI) 1.08 to 1.41, I 2 = 82%; moderate certainty evidence), rimonabant in assisted abstainers (1 study, RR 1.29, 95% CI 1.08 to 1.55), and nicotine replacement therapy (NRT) in unaided abstainers (2 studies, n = 2261, RR 1.24, 95% Cl 1.04 to 1.47, I 2 = 56%). The remainder of analyses of pharmacotherapies in abstainers had wide confidence intervals consistent with both no effect and a statistically significant effect in favour of the intervention. These included NRT in hospital inpatients (2 studies, n = 1078, RR 1.23, 95% CI 0.94 to 1.60, I 2 = 0%), NRT in assisted abstainers (2 studies, n = 553, RR 1.04, 95% CI 0.77 to 1.40, I 2 = 0%; low certainty evidence), extended bupropion in assisted abstainers (6 studies, n = 1697, RR 1.15, 95% CI 0.98 to 1.35, I 2 = 0%; moderate certainty evidence), and bupropion plus NRT (2 studies, n = 243, RR 1.18, 95% CI 0.75 to 1.87, I 2 = 66%; low certainty evidence). Analyses of behavioural interventions in abstainers did not detect an effect. These included studies in abstinent pregnant and postpartum women at end of pregnancy (8 studies, n = 1523, RR 1.05, 95% CI 0.99 to 1.11, I 2 = 0%) and at postpartum follow-up (15 studies, n = 4606, RR 1.02, 95% CI 0.94 to 1.09, I 2 = 3%), studies in hospital inpatients (4 studies, n = 1300, RR 0.95, 95% CI 0.81 to 1.11, I 2 = 0%), and studies in assisted abstainers (10 studies, n = 5408, RR 0.99, 95% CI 0.87 to 1.13, I 2 = 56%; moderate certainty evidence) and unaided abstainers (5 studies, n = 3561, RR 1.06, 95% CI 0.96 to 1.16, I 2 = 1%) from the general population. Authors' conclusions Behavioural interventions that teach people to recognise situations that are high risk for relapse along with strategies to cope with them provided no worthwhile benefit in preventing relapse in assisted abstainers, although unexplained statistical heterogeneity means we are onlymoderately certain of this. In peoplewho have successfully quit smoking using pharmacotherapy, thereweremixed results regarding extending pharmacotherapy for longer than is standard. Extended treatment with varenicline helped to prevent relapse; evidence for the effect estimate was of moderate certainty, limited by unexplained statistical heterogeneity.Moderate-certainty evidence, limited by imprecision, did not detect a benefit from extended treatment with bupropion, though confidence intervals mean we could not rule out a clinically important benefit at this stage. Low-certainty evidence, limited by imprecision, did not show a benefit of extended treatment with nicotine replacement therapy in preventing relapse in assisted abstainers. More research is needed in this area, especially as the evidence for extended nicotine replacement therapy in unassisted abstainers did suggest a benefit.
Cochrane Database of Systematic Reviews