A Randomized Controlled Trial Evaluating the Efficacy of E-Cigarette Use for Smoking Cessation in the General Population: E3 Trial Design

Abstract

BackgroundSmoking cessation improves morbidity and mortality among smokers who achieve long-term abstinence. Many smokers are using electronic cigarettes (e-cigarettes) to attempt to quit, despite a lack of data concerning their efficacy and safety for smoking cessation. MethodsThe Evaluating the Efficacy of E-Cigarette use for Smoking Cessation (E3) trial is a multicentre randomized controlled trial (NCT02417467) with a treatment period of 12 weeks and follow-up of 52 weeks. A total of 376 participants motivated to quit smoking were enrolled at 17 Canadian centres (November 2016 to September 2019). Participants were randomized (1:1:1) to 1 of 3 treatment arms: nicotine e-cigarettes, non-nicotine e-cigarettes, or no e-cigarettes. All groups received individual counselling. Treatment allocation was double-blind for the e-cigarette groups. The trial includes follow-ups by telephone at weeks 1, 2, 8, and 18, and clinic visits at weeks 4, 12, 24, and 52. The primary endpoint is to compare nicotine e-cigarettes to counselling alone in terms of biochemically validated point-prevalence smoking abstinence at 12 weeks; the primary endpoint was changed from 52 weeks after early termination (77% of targeted enrollment) due to a prolonged delay in e-cigarette manufacturing. The secondary objectives are to examine the efficacy of nicotine and non-nicotine e-cigarettes in terms of point-prevalence and continuous smoking abstinence, and reduction in daily cigarette consumption at all follow-ups through week 52, and to describe the occurrence of adverse events. ConclusionThe E3 trial will provide regulators, health care professionals, and smokers with important information about the efficacy and safety of e-cigarettes for smoking cessation.