Timing of ENDS Uptake by Sexual Orientation among Adolescents and Young Adults in Urban Texas

INTRODUCTION: Early-onset of Electronic Nicotine Delivering Systems (ENDS) use puts users at higher risk of developing a regular ENDS use pattern and/or transitioning to combusted tobacco products. Previous studies on ENDS use among adolescents have not considered sexual orientation as a fluid trait that can change over time. Our objective was to evaluate whether ENDS initiation differed by sexual orientation in a longitudinal, population-based cohort of adolescents transitioning into young adulthood in Texas. METHODS: Sample (n = 1712) was drawn from the Texas Adolescent Tobacco and Marketing Surveillance System (waves 5–11) and stratified into three groups, representing sexual orientation: (1) respondents who reported being heterosexuals at each wave (straight), (2) those who consistently self-identified as lesbian, gay or bisexual individuals (LGB), and (3) subjects who reported sexual orientation mobility across waves (mobile). Nonparametric models for interval-censored data were used to estimate the cumulative distribution of age at ENDS initiation by sexual orientation group. Cox models for interval-censored data were used to evaluate whether ENDS initiation varied by sexual orientation group after adjusting for sex assigned at birth, race/ethnicity, cohort, and socioeconomic status. RESULTS: Compared to Straight adolescents, the risk of earlier-onset of ENDS use was higher among mobile individuals (HR = 1.43, 95% CI: 1.12 to 1.83) and LGB individuals (HR = 1.49, 95% CI: 1.13 to 1.98), respectively, after adjusting for sociodemographic risk factors. Differences between Straight adolescents and LGB/mobile individuals became more pronounced with increasing age. CONCLUSION: Analyzing sexual mobility overtime is necessary for understanding the risk associated with youth ENDS initiation and subsequent use. IMPLICATIONS: Future research should use more accurate sexual orientation assessments to explore further the relationship between sexual orientation mobility and early-onset Electronic Nicotine Delivering Systems (ENDS) use. Understanding the implications of sexual orientation mobility on ENDS initiation will be critical for developing inclusive public health programs aimed at preventing or delaying ENDS use and for providing practical recommendations at state and local levels.