Reacción a "Clinical trial compares efficacy of e-cigarettes and varenicline for smoking cessation"

The use of e-cigarettes has been spreading for more than a decade, especially among young people and adolescents, causing considerable concern among health professionals and institutions. Although they are marketed as consumer products, outside the efficacy and safety requirements that apply to medicines, the e-cigarette industry promotes the idea that they are useful for smoking cessation or for reducing the harm caused by tobacco. 

In the randomised clinical trial just published by a group of Finnish researchers led by Anna Tuisku, 458 smokers were randomised into three groups who received 12 weeks of smoking cessation treatment: one group received e-cigarettes and nicotine refill liquids plus tablets with a placebo, a second group was given varenicline tablets (one of those used for smoking cessation) and e-cigarettes without nicotine, and a third group received e-cigarettes without nicotine and tablets with a placebo. All participants attended eight individual visits with a nurse using the motivational interviewing model, a common type of behavioural intervention in smoking cessation treatment. Neither the study participants nor their therapists knew who was receiving e-cigarettes with or without nicotine, and who was taking tablets with varenicline or placebo. 

Six months after starting treatment, smokers who were given access to nicotine-containing e-cigarettes showed levels of tobacco abstinence (at least 7 days without smoking) close to those among those treated with varenicline and non-nicotine e-cigarettes. After one year, however, only those treated with varenicline still showed higher levels of abstinence than the control group, while the use of nicotine-containing e-cigarettes had not maintained a statistically significant favourable effect. 

The duration of pharmacological treatment of smoking is usually limited to a few weeks or a few months. In contrast, it has been found that many smokers who use e-cigarettes with the intention of quitting smoking continue to use them after one year, whether they remain smoke-free or have relapsed to tobacco use. The study did not mention what percentage of smokers continued to use e-cigarettes after 12 weeks of treatment, which would be important to know given the health risks of continued use.   

According to the information provided by the authors, the study was not funded by the tobacco or e-cigarette industry, a potential conflict of interest that affects much research on the use of e-cigarettes. However, the clinical trial was conducted with financial support from the pharmaceutical company that exclusively marketed varenicline until a few years ago, although the authors state that the study was conducted entirely independently.