Randomised, placebo-controlled, double-blind, double-dummy, multicentre trial comparing electronic cigarettes with nicotine to varenicline and to electronic cigarettes without nicotine: the ECSMOKE trial protocol.

Electronic cigarettes (EC) mainly with nicotine content are widely used worldwide. Although the number of publications about its use is increasing exponentially, evidence-based, unbiased, conclusive, head-to-head comparisons about its efficacy and safety as an aid for smoking cessation are lacking. METHODS AND ANALYSIS: Design: randomised, placebo and reference treatment-controlled, multicentre, double-blind, double-dummy, parallel-group trial. Participants: smokers smoking at least 10 cigarettes/day in the past year and motivated to quit, aged 18-70 years. Interventions: (A) EC without nicotine (ECwoN) plus placebo tablets of varenicline administered by oral route: placebo condition, (B) EC with nicotine (ECwN) plus placebo tablets of varenicline: ECwN condition. Voltage regulated EC will be used with liquid containing 12 mg/mL of nicotine for ad libitum use. Flavour: blond tobacco. (C) Reference: ECwoN plus 0.5 mg varenicline tablets: varenicline condition. Varenicline administered according to the marketing authorisationauthorisation. Treatment duration: 1 week+3 months. Primary outcome: continuous smoking abstinence rate (CAR) (abstinence from conventional/combustible cigarettes) during the last 4 weeks (weeks 9-12) of the treatment period defined as self-report of no smoking during the previous 2 weeks and expired air carbon monoxide ≤8 at visit 4 at week 10 after target quit date (TQD), that is, 11 weeks after treatment initiation AND at visit 5, week 12 after TQD, that is, 13 weeks after treatment initiation. Secondary outcomes: safety profile; point prevalence abstinence rate; CAR confirmed by urinary anabasine concentration; changes in cigarettes/day consumption; craving for tobacco and withdrawal symptoms with respect of baseline. The ethics committee approval was obtained on 17 April 2018. All data collected about the study participants will be anonymised. Investigators will communicate trial results to participants, health authorities, healthcare professionals, the public and other relevant groups without any publication restrictions. NCT03630614; Pre-results