Characteristics associated with adult non-fatal opioid and stimulant overdose and substance use disorder emergency department visits in Michigan.

Background: Understanding risk factors for emergency department (ED) visits for overdose and substance use disorder (SUD) can inform prevention efforts. Few studies have considered non-fatal opioid overdoses, stimulant overdoses and SUD, and limited data exists by overdose intentionality and by sex.

Methods: We conducted a serial cross-sectional study with Healthcare Cost and Utilization Project Michigan (MI) 2019-2020 ED discharge data (=5,716,716). Primary outcomes included non-fatal opioid overdoses, non-fatal stimulant overdoses, and SUD primary diagnoses in a single ED visit. We examined demographic and socioeconomic factors associated with study outcomes using binary and multinomial logistic regression (for overdose intentionality) models, which estimated adjusted odds ratios (AOR) and 95 % confidence intervals (CI).

Results: Among all MI discharges, 13,908, 1,379, and 23,462 were nonfatal opioid, stimulant, or SUD overdose visits, respectively. Lower median household income (vs. higher income), male sex (vs. female), metropolitan county of residence (vs. small urban/rural), and Medicaid (vs. private insurance) were associated with increased odds of all outcomes. For example, ORs(95 % CIs) for Medicaid were 4.41(4.18,4.65), 2.25(1.95,2.60), and 2.80(2.70,2.91) for opioid overdoses, stimulant overdoses, and SUD, respectively. All outcomes had the highest increased odds in ages 28-32 years compared to 18-22 years. Stratification by sex and non-fatal overdose intentionality modified some associations, with the strongest associations observed for non-fatal opioid overdoses.

Conclusions: Male sex, Medicaid, and race/ethnicity were consistently associated with all outcomes similarly, but other characteristics varied in patterns, strengths of association, and statistical significance by outcome groups, sex, and non-fatal opioid or stimulant overdose intentionality.