Increased likelihood of psychiatric readmission with Medicaid expansion vs legacy coverage.

Objectives: To compare patterns of psychiatric hospitalization and readmission within 30 days for Medicaid expansion (expansion) vs previously insured (legacy) samples.

Study Design: Retrospective analysis using Medicaid behavioral health service claims.

Methods: We identified 24,044 individuals with hospitalizations in calendar years 2017 and 2018 within the network of a behavioral health managed care organization in Pennsylvania. Logistic regression was used to examine factors associated with readmission.

Results: Individuals covered under expansion (n = 7747) vs legacy (n = 16,297) were older and more likely to be male and European American, with higher rates of cooccurring mental health (MH) and substance use disorder (SUD) diagnoses, as well as lower rates of MH and SUD services in the 30 days prior and any prior MH hospitalization. A higher proportion of individuals with expansion vs legacy status were readmitted (11.3% vs 9.0%; P < .0001). Controlling for factors associated with readmission, regression showed an increased likelihood of readmission for expansion vs legacy status (adjusted odds ratio [AOR], 1.23; 95% CI, 1.12-1.35; P < .0001). Increased risk for readmission was also found across populations for male patients (AOR, 1.12; 95% CI, 1.02-1.22; P = .0124), those with prior MH hospitalizations (AOR, 1.65; 95% CI, 1.51-1.81; P < .0001) or other behavioral health services (AOR, 1.14; 95% CI, 1.03-1.26; P = .0142), those with longer hospitalization episodes (AOR, 1.01; 95% CI, 1.00-1.01; P < .0001), and those with cooccurring SUD (AOR, 1.58; 95% CI, 1.44-1.74; P < .0001).

Conclusions: Individuals with coverage through Medicaid expansion compared with legacy coverage have an increased risk of psychiatric readmission and may warrant targeted interventions that also address service utilization and cooccurring SUD.