Impact of Exposure to Electronic Cigarette Advertising on Susceptibility and Trial of Electronic Cigarettes and Cigarettes in US Young Adults: A Randomized Controlled Trial

Introduction: This study assessed the impact of brief exposure to four electronic cigarette (e-cigarette) print advertisements (ads) on perceptions, intention, and subsequent use of e-cigarettes and cigarettes in US young adults. Methods: A randomized controlled trial was conducted in a national sample of young adults from an online panel survey in 2013. Participants were randomized to ad exposure or control. Curiosity, intentions, and perceptions regarding e-cigarettes were assessed post-exposure and e-cigarette and cigarette use at 6-month follow-up. Analyses were conducted in 2014. Results: Approximately 6% of young adults who had never used an e-cigarette at baseline tried an e-cigarette at 6-month follow-up, half of whom were current cigarette smokers at baseline. Compared to the control group, ad exposure was associated with greater curiosity to try an e-cigarette (18.3% exposed vs. 11.3% unexposed, AOR = 1.63, 95% CI = 1.18, 2.26) among never e-cigarette users and greater likelihood of e-cigarette trial at follow-up (3.6% exposed vs. 1.2% unexposed, AOR = 2.85; 95% CI = 1.07, 7.61) among never users of cigarettes and e-cigarettes. Exploratory analyses did not find an association between ad exposure and cigarette trial or past 30-day use among never users, nor cigarette use among smokers over time. Curiosity mediated the relationship between ad exposure and e-cigarette trial among e-cigarette never users. Conclusions: Exposure to e-cigarette ads may enhance curiosity and limited trial of e-cigarettes in never users. Future studies are needed to examine the net effect of curiosity and trial of e-cigarettes on longer-term patterns of tobacco use. Implications: This randomized trial provides the first evidence of the effect of e-cigarette advertising on a behavioral outcome in young adults. Compared to the control group, ad exposure was associated with greater curiosity to try an e-cigarette among never e-cigarette users and greater likelihood of e-cigarette trial at follow-up in a small number of never e-cigarette users and greater likelihood of e-cigarette trial at follow-up among never users of cigarettes and e-cigarettes.