Alcohol and drug use among patients presenting to an inner-city emergency department: A latent class analysis

► Latent class analysis was used to characterize substance use among adult in the ED. ► Participants (n = 14,557) completed a computerized survey. ► Groups were: low users, binge drinkers, marijuana, cocaine and poly-drug users. ► ED-based interventions should be tailored to address the use of multiple drugs.