Efficacy of Pharmacotherapies for Short-Term Smoking Abstinance: A Systematic Review and Meta-Analysis

Background:Smoking cessation has important immediate health benefits. The comparative shorttermeffectiveness of smoking cessation interventions is not well known. We aimed to determinethe relative effectiveness of nicotine replacement therapy (NRT), bupropion and varenicline at 4weeks post-target quit date.Methods:We searched 10 electronic medical databases (inception to October 2008). Weselected randomized clinical trials [RCTs] evaluating interventions for our primary outcome ofabstinence from smoking at at-least 4 weeks post-target quit date, with biochemical confirmation.We conducted random-effects odds ratio (OR) meta-analysis and meta-regression. We comparedtreatment effects across interventions using head-to-head trials and calculated indirectcomparisons.Results:We combined a total of 101 trials evaluating delivery of NRT versus inert controls atapproximately 4 weeks post-target quit date (total n = 31,321). The pooled overall OR is OR 2.05(95% Confidence Interval [CI], 1.89-2.23, P =< 0.0001). We pooled data from 31 bupropion trialscontributing a total n of 11,118 participants and found a pooled OR of 2.25 (95% CI, 1.94-2.62, P=< 0.0001). We evaluated 9 varenicline trials compared to placebo. Our pooled estimate forcessation at 4 weeks post-target quit date found a pooled OR of 3.16 (95% CI, 2.55-3.91, P =<0.0001). Two trials evaluated head to head comparisons of varenicline and bupropion and found apooled estimate of OR 1.86 (95% CI, 1.49-2.33, P =< 0.0001 at 4 weeks post-target quit date.Indirect comparisons were: NRT and bupropion, OR, 1.09, 95% CI, 0.93-1.31, P = 0.28; vareniclineand NRT, OR 1.56, 95% CI, 1.23-1.96, P = 0.0002; and, varenicline and bupropion, OR 1.40, 95%CI, 1.08-1.85, P = 0.01.Conclusion:Pharmacotherapeutic interventions are effective for increasing smoking abstinencerates in the short-term.