Predictors of JUUL, other electronic nicotine delivery systems, and combustible tobacco initiation among Texas youth.

The objectives of this study were to 1) examine longitudinal predictors of JUUL and other tobacco product initiation, 2) compare these predictors across product type, and 3) describe cross-sectional characteristics of JUUL initiators, among a cohort of Texas adolescents. Analyses were also stratified to examine whether predictors of initiation differed by susceptibility to tobacco use at baseline. This study utilized data from Waves 7 and 8 (Fall 2017 and Spring 2018) of the Texas Adolescent Tobacco and Marketing Surveillance System (n = 2272). Chi-square tests and multinomial logistic regressions were conducted to examine differences in predictors of initiation. Among those who initiated at Wave 8 (n=107), 40.2% initiated JUUL, 43.9% initiated other ENDS, and 15.9% initiated other combustible tobacco. For the full sample, ever marijuana use predicted the initiation of all tobacco products (Relative Risk Ratios "RRRs" from 2.31-4.13) as compared to non-users. For non-susceptible youth, ever marijuana use significantly predicted the initiation of JUUL (RRR = 10.08, 95% CI = 2.11-48.17) and other ENDS use (RRR = 12.07, 95% CI = 2.97-49.04). Peer tobacco use predicted the initiation of JUUL (RRR = 3.06, 95% CI = 1.38-6.81) and other ENDS use (RRR = 5.36, 95% CI = 2.11-13.64) for the full sample, as well as those who were susceptible to tobacco use. For non-susceptible youth, peer tobacco use predicted the initiation of combustible tobacco use (RRR = 16.56, 95% CI = 1.56-175.84). Prominent reasons for JUUL use included curiosity, friend use, and less harmful that cigarettes. Results highlight the role of marijuana in the initiation of all tobacco products, even among low-risk youth; other predictors varied between product type. Interventions should address specific predictors to prevent youth from transitioning to tobacco use.