Places and social contexts associated with simultaneous use of alcohol, tobacco and marijuana among young adults

Introduction and Aims. Little is known about social–ecological correlates of simultaneous use of alcohol with other substances. This study examined places and social contexts associated with simultaneous use of alcohol, tobacco and marijuana among young adults. Design and Methods. We used survey data obtained from 1538 young adult recent alcohol drinkers (49% male; 18–30 years old) in 24 non-contiguous cities in California. Event-level measures included alcohol, tobacco and marijuana use, drinking places and social characteristics of the event. Individual-level measures included alcohol expectancies, depression and demographics. Results. Bars and restaurants had less alcohol and marijuana use (odds ratio = 0.34; 95% confidence interval 0.18, 0.62; P < 0.001) and alcohol, marijuana and tobacco use (odds ratio = 0.27; 95% confidence interval 0.14, 0.54; P < 0.001) compared with alcohol use only. Perceived percent of intoxicated people at an event was associated with greater likelihood of using alcohol with tobacco and marijuana at the event. At the individual level, greater age was generally associated with increased odds of simultaneous use. Participants who were male, less educated, more depressed and had positive alcohol expectancies were more likely to simultaneously co-use alcohol with tobacco and marijuana. Those with negative expectancies were less likely to simultaneously use these substances. Discussion and Conclusions. Social events in private settings with a high percentage of people who are intoxicated had increased likelihood of simultaneous use of alcohol, tobacco and marijuana. Prevention efforts in these settings may reduce simultaneous use of these substances and related harms. [Lipperman-Kreda S, Paschall MJ, Saltz RF, Morrison CN. Places and social contexts associated with simultaneous use of alcohol, tobacco and marijuana among young adults. Drug Alcohol Rev 2017;00:000–000].