Electronic Cigarettes for Smoking Cessation

Summary

A systematic review and meta-analysis 1 including 38 trials assessed the association between e-cigarette use and cigarette smoking cessation among adult cigarette smokers, irrespective of their motivation for using e-cigarettes. All 20 studies with control groups (15 cohort studies, 3 cross-sectional studies, and 2 clinical trials) were included in random effects meta-analysis and sensitivity analyses. Odds of quitting cigarettes were 28% lower in those who used e-cigarettes compared with those who did not use e-cigarettes (OR 0.72, 95% CI 0.57 to0.91). Association of e-cigarette use with quitting did not significantly differ among studies of all smokers using e-cigarettes (irrespective of interest in quitting cigarettes) compared with studies of only smokers interested in cigarette cessation (OR 0.63, 95% CI 0.45 to 0.86 vs 0.86, 95% CI 0.60 to 1.23; p=0.94). Other study characteristics (design, population, comparison group, control variables, time of exposure assessment, biochemical verification of abstinence, and definition of e-cigarette use) were also not associated with the overall effect size (p≥0.77 in all cases).

A Cochrane review [Abstract] 2 included 24 studies (3 RCTs, 2 of which were eligible for meta-analysis, and 21 cohort studies). Participants using e-cigarettes were more likely to have abstained from smoking for at least 6 months compared with participants using placebo e-cigarettes (RR 2.29, 95% CI 1.05 to 4.96; placebo 4% versus e-cigarettes 9%; 2 trials; n=662; verified by exhaled CO; quality of evidence low). The most frequently reported adverse effects were mouth and throat irritation.