Online support for smoking cessation: a systematic review of the literature.

AIM To examine the efficacy and acceptability of online, interactive interventions for smoking cessation and to identify treatment effect moderators and mediators. METHODS A systematic review and meta-analysis of the literature (1990-2008) was conducted, finding 11 relevant randomized controlled trials. Data were extracted and risk ratios and risk differences estimated with a random effects model. RESULTS There was no evidence of publication bias. Included trials were of variable methodological quality. Web-based, tailored, interactive smoking cessation interventions were effective compared with untailored booklet or e-mail interventions [rate ratio (RR) 1.8; 95% confidence interval (CI) 1.4-2.3] increasing 6-month abstinence by 17% (95% CI 12-21%). No overall effect of interactive compared with static web-based interventions was detected but there was significant heterogeneity, with one study obtaining a clear effect and another failing to find one. Few moderating or mediating factors were evaluated in studies and those that were had little effect. Pooled results suggest that only interventions aimed at smokers motivated to quit were effective (RR 1.3, 95% CI 1.0-1.7). Fully automated interventions increased smoking cessation rates (RR 1.4, 95% CI 1.0-2.0), but evidence was less clear-cut for non-automated interventions. Overall, the web-based interventions evaluated were considered to be acceptable and user satisfaction was generally high. CONCLUSION Interactive, web-based interventions for smoking cessation can be effective in aiding cessation. More research is needed to evaluate the relative efficacy of interactive web-based interventions compared with static websites.