Longitudinal associations between U.S. youth exposure to E-cigarette marketing and E-cigarette use harm perception and behavior change.

E-cigarette marketing tactics to reach and appeal to youth are rapidly changing. This study examined to what extent youth e-cigarette marketing exposure was associated with e-cigarette use behavior change one year later, during a time when youth e-cigarette use was starting to surge in the U.S. Using nationally representative longitudinal public-use data from the Population Assessment of Tobacco and Health (PATH) Study, we examined associations between recalled e-cigarette marketing exposure (2016-2018) at Wave (W) 4 and e-cigarette use harm perception and behavior change (ever, current, and regular use) one year later (W4.5; 2017-2018) among W4 never tobacco users (n = 9405). Recall of exposure to e-cigarette marketing through different channels was also examined in multivariable models controlling for socio-demographic factors and established e-cigarette use risk factors. Results show that the most frequently recalled channels of e-cigarette marketing exposure were retail stores (50.3%), television (22.2%), and websites/social media (20.2%). Over one year, 21.2%, 7.8%, 3.4%, and 1.2% of respondents reported reduced harm perceptions, and ever, current, and regular use of e-cigarettes, respectively, at follow-up. Recalled exposure to e-cigarette marketing was associated with reduced e-cigarette harm perception (AOR = 1.20; 95% CI = 1.05-1.37) and ever (AOR = 1.26; 95% CI = 1.01-1.56) and current use (AOR = 1.40; 95% CI = 1.02-1.92) at follow-up. E-cigarette marketing exposure through websites/social media was associated with reduced harm perceptions and all stages of e-cigarette use change, including regular use. Identifying marketing techniques and channels that change youth e-cigarette harm perceptions and influence e-cigarette use progression is essential to inform e-cigarette regulatory policies and prevention campaigns.