The ESTxENDS Trial- Electronic Nicotine Delivery Systems as an Aid for Smoking Cessation-extension of Follow-up

Cigarette smoking is the leading cause of preventable death in Switzerland and still more than a quarter of the Swiss population smokes cigarettes. Recently, electronic nicotine delivery systems (ENDS; also called vaporizer or electronic cigarette) have become popular with smokers who want to stop smoking or reduce their exposure to inhaled chemicals since ENDS use appears to be safer than tobacco smoking. Only two rigorous randomized controlled trials (RCTs) on the efficacy of ENDS to help smokers quit have been published so far. They have promising, yet inconclusive results, as the number of included participants were small. The safety and potential adverse effects of ENDS are also largely unknown. While the aerosol the users inhale appears safe in laboratory conditions, the difference in exposure to chemicals (such as reduction in exposure to volatile organic compounds) and effects of chemicals on the body (adverse events, improved health-related outcomes and measures of oxidative stress) between smokers who quit (with or without ENDS) and those who use ENDS for a long time have not yet been assessed in an RCT. This study will therefore test the efficacy of ENDS for cigarette smoking cessation, the safety of ENDS on adverse events and the effect of ENDS on health-related outcomes and exposure to inhaled chemicals. The primary hypothesis of this trial is that providing cigarette smokers willing to quit smoking tobacco cigarettes with ENDS leads to a higher rate of smokers who quit cigarette smoking than only smoking cessation counseling with nicotine replacement therapy (NRT), which represents nowadays the standard of care. For this trial, cigarette smokers motivated to quit smoking cigarettes will be included. Participants in the intervention group will receive an ENDS and nicotine-containing e-liquids, which they will be allowed to use ad libitum. Additionally, they will receive smoking cessation counseling. Participants in the control group will receive smoki