This study compared utilization patterns of high-cost services and medications for patients receiving care from Accountable Care Organization (ACO)-participating physicians and those receiving care from non-ACO physicians during the initial phases of ACO development in a commercially insured environment. Patients ≥18 years (≥40 years for chronic obstructive pulmonary disease [COPD]) with prevalent rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, type 2 diabetes, COPD, or chronic low back pain between January 1, 2012, and August 31, 2014 were identified in the HealthCore Integrated Research DatabaseSM. Patients were assigned to the ACO cohort if their primary treating physician was contracted to the health plan through an ACO agreement. Each clinical condition was stratified for severity of illness. Cohort utilization patterns were compared for the 12-month period following the index encounter. The primary outcome measures show that there was no statistically significant utilization difference between the ACO and non-ACO cohorts for 90% of the 82 comparisons made. It is expected that some measures will achieve significant difference simply because of having this many comparisons, but no clear pattern was identified. This study did not observe statistically significant differences in utilization of high-cost services and medications between ACO and non-ACO cohorts with limited experience in the ACO model. Future analyses with longer study durations, at later stages of ACO development, tracking a more granular level of physician organizational structure, and with designs that integrate clinical and administrative data are essential to better understand the impact of payment innovation strategies using an ACO structure.
Keywords: Accountable Care Organization; cost of care; utilization.