E-cigarettes may work as well as nicotine patches in reducing and quitting smoking, but evidence is limited

The first Cochrane review of electronic (e) cigarettes has concluded that people who use them can stop or reduce their smoking and that the devices may be roughly equivalent in efficacy to nicotine patches. But the evidence base was very limited—two randomised controlled trials and 11 observational studies—so the size of the benefit is uncertain.

The results1 showed that smokers were 31% more likely to reduce smoking when using an e-cigarette rather than a placebo e-cigarette that delivered no nicotine (odds ratio 1.31 (95% confidence interval 1.02 to 1.58)). For quitting smoking, again measured against placebo, the odds ratio was 2.29 (1.05 to 4.96). Only a …