Time-Specific Predictors of E-Cigarette and Cigarette Use Trajectory Classes From Preadolescence to Late Adolescence (2013-2020) of the Population Assessment of Tobacco and Health (PATH) Study.

Objective: In the US, youth e-cigarette use is more prevalent than cigarette use. Among younger adolescents in US middle schools, use of any nicotine/tobacco product is on the rise. Different factors may drive transitions from susceptibility to initiation, and less is known about early adolescent transitions.

Methods: Data were drawn from US early adolescents (aged 12-13 years) at Wave (W) 1 of the Population Assessment of Tobacco and Health (PATH) Study across 7 waves (2013-2020) into older adolescents (aged 18-19 years). Unweighted longitudinal latent class analyses identified trajectory classes of e-cigarette and cigarette susceptibility and use in separate models. Weighted multinomial logistic regression analyses examined time-specific predictors of divergent trajectories.

Results: Five e-cigarette classes (weighted 45.1% Never Use, 15.4% Susceptible, 6.9% Initiated only, 19.9% W5 Progressed/discontinued, and 12.7% Progressed/persisted) and 4 cigarette classes (weighted 61.2% Never Use, 21.3% Susceptible, 10.6% W4.5 Progressed/discontinued, and 6.9% Former Use) were identified. In 2020 (the first year of the COVID-19 pandemic), discontinued use of both products was observed. Only the e-cigarette model identified a class with persistent use through 2020. Daily social media use and advertising exposure were specifically important to susceptibility and initiation of e-cigarettes among younger adolescents. Best friend use, low perceptions of product harm, and substance use problems showed strong associations with trajectories of e-cigarettes and cigarettes.

Conclusions: Trajectories for both products revealed a period of susceptibility before use that may be particularly amenable to early intervention. It is important to monitor daily social media use and advertising exposure to prevent e-cigarette susceptibility and initiation.