LAUSR

INTRODUCTION Given the increased availability of tobacco products and devices, rising trends of vaping, and changing marijuana policies in the United States (U.S.), this study reports the prevalence of U.S. young adults using tobacco products/devices for marijuana consumption and associations with substance use problems. METHODS U.S. nationally representative data from Wave 3 (2015-2016) of the Population Assessment of Tobacco and Health Study were used to assess young adults' (18-24 years old, unweighted sample = 8453) ever marijuana use and ever use of electronic nicotine delivery systems (ENDS), hookah, or cigars for marijuana consumption. A multinomial logistic regression predicted the Substance Use Problem subscale of the Global Appraisal of Individual Needs inventory categorized into low (0-1), moderate (2-3) and high (4 or more) symptoms. RESULTS Weighted analyses indicated about half of young adults (52.1%) had ever used marijuana. Of this group, the majority (80.1%) ever used any tobacco product/device for marijuana use including: ENDS (24.5%), hookah (25.2%), or cigar (74.0%). Ever use of tobacco products/devices for marijuana significantly predicted moderate (RRR = 1.70, p < 0.01) and high (RRR = 4.67, p < 0.01) substance use problems controlling for sex, race, employment, education, and past 30-day cigarette, cigar, ENDS, hookah, marijuana and alcohol use. CONCLUSIONS Use of tobacco products/devices for marijuana consumption is common among U.S. young adults and it is associated with substance use problems. A better understanding of how tobacco devices are being used to support use of both substances and the outcomes of co-use are needed to inform policy and public health interventions.