Longitudinal trajectories of marijuana use in tobacco products among young adult Texas college students from 2015 to 2019

Aims To measure longitudinal trajectories of marijuana use in four tobacco/nicotine products (hand-rolled cigarettes/spliffs, cigars/blunts, hookah, and e-cigarettes) among young adult Texas college students from 2015 to 2019. Design This study used six consecutive waves of data from the marketing and promotions across colleges in Texas project (Project M-PACT), a longitudinal study of the tobacco behaviors of young adult college students. The first four waves were collected every 6 months (fall 2015-spring 2017), and the final two waves were conducted yearly (spring 2018 and 2019). Growth curve models measured trajectories of marijuana use in tobacco products across the 3.5-year period. Setting and Participants A total of 4857 young adults from 24 colleges in the largest metropolitan areas of Texas, United States (Austin, Dallas, Houston, and San Antonio): mean age = 21.0, SD = 2.3; 64.2% assigned female; 36.1% non-Hispanic white, 31.0% Hispanic, and 33.0% other or combination race/ethnicity. Measurements Participants completed online surveys assessing their past 6-month use of marijuana in four tobacco products of interest (spliffs, blunts, hookah, and e-cigarettes) and socio-demographic variables (sex, race/ethnicity, age, 2-year/4-year college attendance, and sexual and gender minority identity). Findings Observed vaping marijuana in e-cigarettes approximately doubled between the spring of 2015 and the spring of 2019, from 11.8% to 23.9% following a quadratic time trend (linear OR = 0.84, 95% CI = 0.73-0.97, quadratic OR = 1.18, CI = 1.13-1.22). This same time period saw a quadratic decline in using marijuana in hookah (P < 0.001) and no changes in using hand-rolled cigarettes/spliffs or cigars/blunts for marijuana delivery. Conclusions The popularity of nicotine e-cigarettes appears to be expanding the avenues for marijuana delivery among young adults in Texas, United States.

Automated summary

This study examined the longitudinal trajectories of marijuana use in different tobacco/nicotine products among young adult college students in Texas from 2015 to 2019. The findings showed an increase in vaping marijuana in e-cigarettes and a decline in using marijuana in hookah. This suggests that the popularity of nicotine e-cigarettes has expanded the avenues for marijuana delivery among young adults.