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.