Same-day use of cigarettes, alcohol, and cannabis among sexual minority and heterosexual young adult smokers.

Objective: Sexual minority (SM) young adults have higher rates of substance use than heterosexuals, but little is known about daily use of multiple substances, which confer numerous health risks for this population. Using daily diary data from a smartphone-based study, we examined the associations between sexual identity (i.e., SM vs. heterosexual) and patterns of same-day multiple substance use (i.e., cigarettes and alcohol, cigarettes and cannabis, alcohol and cannabis, and all 3 substances). Method: Young adult smokers (N = 147, aged 18–26, 51.7% female, 41.5% SM, 40.8% White) reported consecutive daily assessments on substance use over 30 days. We used generalized estimating equations to examine associations between sexual identity and patterns of same-day multiple substance use, controlling for demographic factors and psychological distress. Results: Of 2,891 daily assessments, 16.7% reported same-day use of cigarettes and alcohol, 18.1% cigarettes and cannabis, 1.5% alcohol and cannabis, and 15.0% use of all 3 substances. SM participants (vs. heterosexuals) had significantly greater odds of reporting days with use of cigarettes and cannabis [Adjusted Odds Ratio (AOR) = 2.05, 95% Confidence Interval (CI) [1.04, 4.01]] and use of all three substances (AOR = 2.79, 95% CI [1.51, 5.14]) than days with single substance use or no use. Conclusions: These findings warrant tailored interventions addressing multiple substance use among SM young adults and temporally accurate measures of multiple substance use patterns. Public Significance Statement—This study indicates that SM young adult smokers were more likely to use cigarettes, alcohol, and cannabis on the same day than their heterosexual peers. Interventions addressing multiple substance use among SM young adults are needed to reduce sexual identity-related health disparities.