Association of Mental Health Disorders with Health Care Spending in the Medicare Population

Abstract

Importance: The degree to which the presence of mental health disorders is associated with additional medical spending on non-mental health conditions is largely unknown. Objective: To determine the proportion and degree of total spending directly associated with mental health conditions vs spending on other non-mental health conditions. Design, Setting, and Participants: This retrospective cohort study of 4358975 fee-for-service Medicare beneficiaries in the US in 2015 compared spending and health care utilization among Medicare patients with serious mental illness (SMI; defined as bipolar disease, schizophrenia or related psychotic disorders, and major depressive disorder), patients with other common mental health disorders (defined as anxiety disorders, personality disorders, and posttraumatic stress disorder), and patients with no known mental health disorders. Data analysis was conducted from February to October 2019. Exposure: Diagnosis of an SMI or other common mental health disorder. Main Outcomes and Measures: Risk-adjusted, standardized spending and health care utilization. Multivariable linear regression models were used to adjust for patient characteristics, including demographic characteristics and other medical comorbidities, using hospital referral region fixed effects. Results: Of 4358975 Medicare beneficiaries, 987379 (22.7%) had an SMI, 326991 (7.5%) had another common mental health disorder, and 3044587 (69.8%) had no known mental illness. Compared with patients with no known mental illness, patients with an SMI were younger (mean [SD] age, 72.3 [11.6] years vs 67.4 [15.7] years; P