LAUSR

INTRODUCTION Marijuana vaping among adolescents is a growing public health concern. Marijuana vaping exposes youth to greater levels of tetrahydrocannabinol (THC) and may be related to e-cigarette or vaping product use-associated lung injury (EVALI). This study examined the risk factors for initiating marijuana vaping among US adolescents. METHODS We analyzed Waves 3 (2015-2016) and 4 (2016-2018) of the Population Assessment of Tobacco and Health (PATH) Study. We estimate a multivariable logistic regression to model marijuana vaping initiation at Wave 4 among those who never vaped marijuana at Wave 3 (N = 7,821) as a function of key risk factors associated with youth substance use. RESULTS Marijuana vaping initiation is associated with current use of electronic nicotine delivery system (ENDS) (aOR = 2.16, 95 % CI = 1.20, 3.89), cigarettes (aOR = 2.65, 95 % CI = 1.10, 6.35), other marijuana products (aOR = 7.78, 95 % CI = 3.74, 6.15), and alcohol (aOR = 1.98, 95 % CI = 1.35, 2.91). Other factors contributing to marijuana vaping initiation include being 15-17 years old (aOR = 1.51, 95 % CI = 1.19, 1.90) and Hispanic (aOR = 1.37, 95 % CI = 1.08, 1.76), as well as having less than college-level parental education (aOR = 1.35, 95 % CI = 1.07, 1.70), vaping peers (aOR = 2.31; 95 % CI = 1.81, 2.96), and a high internalizing (aOR = 1.49, 95 % CI = 1.10, 2.02) and externalizing tendency (aOR = 1.66, 95 % CI = 1.14, 2.41). CONCLUSIONS Multi-level efforts are needed to target the varying risk factors leading to marijuana vaping initiation in adolescents. Knowledge of these risk factors can help policymakers and health program administrators to identify at-risk individuals and design interventions that can prevent marijuana vaping initiation at the individual, household, school, clinical and public health levels.