Enhanced Primary Care for Severe Mental Illness Reduces Inpatient Admission and Emergency Room Utilization Rates

Cardiovascular disease (CVD) is a leading cause of premature mortality among patients with severe mental illness (SMI). Effective care delivery models are needed to address this mortality gap. This study examines the impact of an enhanced primary care (PC) program that specializes in the treatment of patients with SMI, called Medicine in Psychiatry Service-Primary Care (MIPS-PC). Using multipayer claims data in Western New York from January 1, 2016 to December 31, 2021, patients with SMI and CVD were identified using International Classification of Diseases, Tenth Revision codes. National Provider Identification numbers of MIPS-PC providers were then used to identify those patients who were treated by MIPS-PC during the period. These MIPS-PC-treated patients were compared against a cohort of one-to-one propensity score matched contemporaneous comparison group (ie, patients receiving PC from providers unaffiliated with MIPS-PC). A difference-in-difference approach was used to identify the treatment effects of MIPS-PC on all-cause emergency department (ED) visits and hospitalization rates. The MIPS-PC group was associated with a downtrend in the acute care utilization rates over a 3-year period following the index date (ie, date of first MIPS-PC or other PC provider encounter), specifically a lower hospitalization rate in the first year since the index date (25%; P < 0.001). ED visit rate reduction was significant in the third-year period (18%; P = 0.021). In summary, MIPS-PC treatment is associated with a decreasing trend in acute care utilization. Prospective studies are needed to validate this effect of enhanced PC in patients with SMI and CVD.