E-cigarettes: the Cochrane Review

A new Cochrane Review of e-cigarettes was published this week. Cochrane Reviews focus on randomised controlled trials, which are generally seen as the gold standard of scientific evidence. You don't see many of them in 'tobacco control', but they are possible when it comes to smoking cessation.

The previous Cochrane Review could only find two high quality RCTs. The new review found four, with nicotine replacement therapy and/or nicotine-free e-cigarettes used by the control group. It concludes:

There was moderate-certainty evidence, again limited by imprecision, that quit rates were higher in people randomized to nicotine EC than to non-nicotine EC (RR 1.71, 95% CI 1.00 to 2.92; I2 = 0%; 3 studies, 802 participants). In absolute terms, this might again lead to an additional four successful quitters per 100 (95% CI 0 to 12).

The element of randomisation almost certainly leads the the real world efficacy of vaping in cessation being downplayed. These studies show that e-cigarettes help people quit smoking even when they don't intend to quit smoking at the outset. For people who actively want to quit smoking, e-cigarettes are even more effective. I'll be writing more about this next week.