Study Finds E-Cigarette Users Are More Likely to Stop Smoking Than People Who Use Other Methods to Quit


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According to a study reported today in the journal Addiction, people who try to quit smoking with the aid of electronic cigarettes are twice as likely to succeed as people who use nicotine replacement products such as gum or patches. The researchers, led by University College London health psychologist Robert West (who is editor in chief of Addiction), surveyed a representative sample of the British population, focusing on 5,863 subjects who had tried to quit in the previous year unaided, with e-cigarettes, or with over-the-counter nicotine replacement therapy (NRT). At the time of the survey, 20 percent of the e-cigarette users were no longer smoking, compared to 10.1 percent of NRT users and 15.4 percent of those who tried to quit without any sort of nicotine replacement. Adjusting for various possible confounding variables, including age, sex, socioeconomic status, and strength of nicotine dependence, West et al. found that e-cigarette users were about 60 percent more likely to succeed than either of the other two groups.

The quit rate among e-cigarette users in this study is one-quarter the rate found in a recent survey of 19,000 e-cigarette users. But the sample for the latter study was drawn mainly from participants in online e-cigarette forums, who are especially enthusiastic about the product and therefore more likely to have successfully switched from smoking to vaping. Since West et al. used a random sample of smokers who had tried to quit, their results are more representative.

West et al.'s results indicate that e-cigarettes have a bigger edge over NRTs than suggested by a randomized trial reported in The Lancet last year. In that study, the six-month quit rate for e-cigarette users was 7.3 percent, compared to 5.8 percent for patch users. The difference between the quit rates in the two studies might be due to confounding variables that West et al. did not take into account. Then again, if e-cigarettes are especially effective for people with certain traits, a randomized trial would obscure that fact. West argues that clinical trials are not appropriate for measuring the effectiveness of e-cigarettes as a smoking cessation aid because subjects who do not like the treatment to which they are assigned tend to drop out. He also suggests that the e-cigarette market, which is currently shifting from cigarette-like products with disposable cartridges toward vaping devices with refillable tanks, is changing so rapidly that experimental results may be obsolete by the time they are published.

Whether or not you agree with West, it is plainly absurd to continue claiming, as CDC officials do, that the harm-reducing benefits of e-cigarettes are merely "hypothetical." Based on the evidence collected so far, e-cigarettes are at least as effective as the NRTs favored by the CDC, and probably more effective. "E-cigarettes could substantially improve public health because of their widespread appeal and the huge health gains associated with stopping smoking," West says, "It is not clear whether long-term use of e-cigarettes carries health risks, but from what is known about the contents of the vapor, these will be much less than from smoking." While "some public health experts have expressed concern that widespread use of e-cigarettes could 're-normalize' smoking," he adds, "we are tracking this very closely and see no evidence of it. Smoking rates in England are declining, quitting rates are increasing and regular e-cigarette use among never smokers is negligible."

Addendum: As Michael Siegel notes, Carl Phillips has some useful observations about how to interpret West et al.'s results and whether randomized clinical trials are a better approach:

Self-selection is not a problem, but rather part of what matters in the real world. There is no possibility that every smoker in a population will be assigned one method to quit. Thus, there is no reason to try to figure out which would be the best single method to assign to everyone (which is basically what a well-done clinical study would show). Rather, in the real world, each of the cessation methods is available to everyone, and (since it does not matter which one someone uses, from the perspective of health) it is best if they can find which one works best for them (which refers to both effective smoking cessation and ongoing happiness).