Everyday and Healthcare Discrimination and Polysubstance Use Among U.S. Adults

Background Interpersonal mistreatment in everyday life and healthcare settings are social determinants of health linked to a range of outcomes. However, their associations with adult polysubstance use—particularly at the population level—remain less understood. Methods We analyzed survey data from the All of Us Research Program (Version 8) (n=259,033) and operationalized the Everyday Discrimination Scale (EDS; range, 0-5) and Healthcare Discrimination Scale (HDS; range, 0-4) as continuous measures. Substance use patterns were defined as mutually exclusive use categories of exclusive (any one), dual (any two), and poly (all three) current tobacco/nicotine, alcohol, and cannabis use. We fit multivariable multinomial logistic regression models to estimate associations between both forms of discrimination and substance use patterns. Results The average EDS and HDS scores were 0.85 (SD=0.87) and 0.59 (SD=0.66); the prevalence of exclusive, dual, and poly use was 47.4%, 8.4%, and 0.6%. In adjusted models, increasing EDS was associated with higher odds of exclusive use (AOR: 1.05, 95% CI: 1.04-1.07), dual use (AOR: 1.12, 95% CI: 1.10-1.15), and poly use (AOR: 1.21, 95% CI: 1.13-1.30). Increasing HDS was inversely associated with exclusive use (AOR: 0.91, 95% CI: 0.90-0.92) and dual use (AOR: 0.96, 95% CI: 0.93-0.98) and not associated with poly use. Conclusions Interpersonal discrimination represents a clinically relevant and potentially modifiable social determinant of polysubstance use. Efforts to reduce everyday discrimination and improve patient experiences within healthcare settings may play an important role in preventing higher-risk substance use patterns and advancing equity in substance use-related outcomes.