Electronic cigarettes (e-cigarettes) are a diverse and rapidly evolving range of battery-operated devices that vaporize nicotine for inhalation. Millions of people have purchased them.1 Indeed, e-cigarette sales are increasing so rapidly some analysts predict that they will overtake cigarette sales within a decade.2
Despite this mass use of a novel inhalable product, there is a remarkable paucity of reliable efficacy and safety data to inform debate over their place in treating tobacco dependence.3,4 Surveys show many smokers try e-cigarettes to cut down tobacco use or quit smoking,5,6 and studies show they are capable of attenuating tobacco withdrawal just as effectively as nicotine replacement therapy (NRT).7,8 Part of their appeal may be their simulation of the behavioral and sensory dimensions of smoking. But e-cigarette use could lead to harm: toxins have been found in e-cigarette fluid and vapor.9,10 However, the levels are similar to those found in NRT and are far lower than those in cigarette smoke.11 Indeed, a recent review deemed e-cigarettes to be very unlikely to pose significant risks to smokers.12
My colleagues and I conducted a pragmatic, randomized, controlled superiority trial in Auckland, New Zealand, between September 2011 and July 2013 to assess whether e-cigarettes with nicotine were more effective for smoking cessation than nicotine patches.13 We included a blind comparison with “placebo” e-cigarettes (containing no nicotine). We hypothesized that nicotine e-cigarettes would be more effective than patches and placebo e-cigarettes for smoking reduction, tobacco dependence, and relief of withdrawal symptoms, and that they would have no greater risk of adverse events than nicotine patches.
Smokers aged 18 years and older who wanted to quit were randomized to 16-mg nicotine e-cigarettes, nicotine patches (21-mg patch, one daily), or placebo e-cigarettes (no nicotine) from 1 week before until 12 weeks after quit day, with low-intensity behavioral support via voluntary telephone counseling. The primary outcome was biochemically verified continuous abstinence at 6 months (exhaled breath carbon monoxide measurement less than 10 ppm). Primary analysis was by intention to treat.
A total of 657 people were randomized (289 to nicotine e-cigarettes, 295 to patches, and 73 to placebo e-cigarettes). At 6 months, verified abstinence was 7.3% (21 of 289) with nicotine e-cigarettes, 5.8% (17 of 295) with patches, and 4.1% (3 of 73) with placebo e-cigarettes (risk difference for nicotine e-cigarette vs patches 1.51 [95% CI = –2.49 to 5.51]; for nicotine e-cigarettes vs placebo e-cigarettes 3.16 [95% CI = –2.29 to 8.61]). Achievement of abstinence was substantially lower than anticipated for the power calculation, so there was insufficient statistical power to conclude superiority of nicotine e-cigarettes to patches or to placebo e-cigarettes. However, they were at least as effective as patches. Importantly, we found no evidence of an association between adverse events and study product.
We concluded that e-cigarettes, with or without nicotine, were modestly effective at helping smokers quit, with similar achievement of abstinence as with nicotine patches, and few adverse events.
At 6 months, 29% of the nicotine e-cigarettes group and 35% of the placebo e-cigarettes group persisted with e-cigarette use, while only 8% in the patches group were still using patches. Among those in the nicotine e-cigarettes group verified as abstinent, 38% still used e-cigarettes at 6 months; among non-quitters, 29% still used e-cigarettes. The e-cigarette users were very enthusiastic about them: 85% of participants allocated to e-cigarettes would recommend them to a friend wanting to quit, and 40% liked their tactile cigarette-like qualities, sensory familiarity, perceived health benefits, taste, absence of cigarette odor, and ease of use.
Dr Bullen is Associate Professor at the University of Aukland New Zealand and Director of the National Institute for Health Innovation. He reports no conflicts of interest concerning the subject matter of this article. For a pdf of the study in The Lancet, please click here.
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