Abstract 3976: A Hierarchical Bayesian Meta-Analysis of Randomized Controlled Trials of Smoking Cessation Pharmacotherapies
Background: Many placebo-controlled trials have demonstrated the efficacy of pharmacotherapies approved for smoking cessation. However, few direct or indirect comparisons of smoking cessation pharmacotherapies have been conducted.
Objective: We undertook a meta-analysis of randomized controlled trials (RCTs) comparing each of six pharmacotherapies (sustained release (SR) bupropion, nicotine gum, nicotine inhaler, nicotine nasal spray, nicotine tablet, or transdermal nicotine) to placebo-control.
Methods: We conducted a systematic search to identify all randomized, placebo-controlled, double-blind RCTs reporting biochemically-validated smoking abstinence at 6 months and/or one year. A hierarchical Bayesian random-effects model was used to summarize the results for each pharmacotherapy. We then used the individual meta-analysis results to indirectly compare the efficacies of smoking cessation pharmacotherapies, while adjusting for study level covariates.
Results: We identified 63 published reports of 61 trials which randomized a total of 25,674 patients. Nicotine nasal spray (odds ratio (OR)=2.37, 95% credible interval (CrI)=1.12–5.13), bupropion SR (OR=2.32, 95%CrI=1.85–2.99), transdermal nicotine (OR=2.07, 95%CrI=1.69–2.62), nicotine tablet (OR=2.05, 95%CrI=1.13–3.27), and nicotine gum (OR=1.75, 95%CrI=1.35–2.32) were all found to be more efficacious than placebo. Although the point estimate favored nicotine inhalers compared with placebo, these results were not conclusive due to a wide credible interval (OR=2.17, 95%CrI=0.95–5.43). When RCTs for all five nicotine replacement therapies (NRTs) were pooled, there was a strong suggestion that bupropion SR was superior to NRTs (ratio of Ors=1.28, 95%CrI=0.97–1.66).
Conclusions: Bupropion SR, nicotine gum, nicotine inhaler, nicotine nasal spray, nicotine tablet, and transdermal nicotine are all more efficacious at promoting smoking abstinence than placebo. However, bupropion SR may be more efficacious than NRTs. These latter results need confirmation via direct comparison in head-to-head RCTs.