A randomized controlled trial of smoking cessation treatment for young adult dual users of combustible and electronic cigarettes

在美国，每年有超过48万人死于与吸烟有关的疾病

Over 480,000 people die per year from combustible cigarette (CC) smoking related illness in the United States. Young adults are particularly vulnerable to nicotine dependence and harm from tobacco. The prevalence of electronic cigarette (EC) use has increased exponentially over the past decade and is highest among young adults. ECs could substantially reduce harm for young adult smokers who completely switch from CCs to ECs and remain abstinent from CCs. However, most who use ECs continue to smoke CCs (i.e., dual users), which could perpetuate nicotine dependence and harm from CC smoking. There are no empirically based treatments for dual users and it is unclear whether quitting CCs only or quitting both CCs and ECs simultaneously is more effective to achieve long-term abstinence from CCs. Nicotine replacement therapy (NRT) is an effective first-line smoking cessation treatment for adult CC smokers but has never been tested among young adults or among dual users. Given the strong evidence that smoking cessation early in life can completely avoid tobacco-related mortality, there is a need to test effective smoking cessation treatment for young adult dual users. The overarching aim of the proposed 2x2 factorial RCT is to test NRT with text message support for two smoking cessation approaches among young adult dual users of CCs and ECs. Specifically, we aim to 1) test the effectiveness of NRT for CC cessation among young adult dual users and 2) test whether quitting CCs only versus quitting CCs and ECs simultaneously is more effective to achieve CC abstinence. Participants (n=390) will be randomized to receive A) NRT plus text messages to quit CCs only, B) NRT plus text messages to quit CCs and ECs simultaneously, C) text messages alone to quit CCs only, or D) text messages alone to quit CCs and ECs simultaneously. Our primary outcome will be CO-verified 7-day point-prevalence abstinence at the end of treatment (i.e., 3 months after randomization). Findings from our primary aims will directly inform smoking cessation treatment for young adult dual users, a population that is particularly vulnerable to the harmful effects of nicotine addiction. This is important given the current lack of published research on smoking cessation treatment for dual users or NRT for young adults. As secondary aims, we will explore the interaction between NRT use versus no use and quitting CCs only versus CCs and ECs simultaneously as well as change in nicotine dependence, demand, and other smoking related outcomes among participants who fail to quit. Broadly, findings will have applied implications for treating young adult dual users and scientific implications regarding the effects of quitting one (CCs) versus two (CCs and ECs) nicotine products simultaneously.