The association between Medicare accountable care organization enrollment and breast, colorectal, and prostate cancer screening

Abstract

Background: Despite the rapid diffusion of accountable care organizations (ACOs), the effect of ACO enrollment on cancer diagnosis, treatment, and survivorship remains unknown. The objective of this study was to determine whether Medicare Shared Savings Program (MSSP) ACO enrollment was associated with changes in screening for breast, colorectal, and prostate cancers. Methods: The authors built a cohort of Medicare beneficiaries from 2006 through 2014 comprising 39,218,652 person-years of observation before and 17,252,345 person-years of observation after MSSP enrollment. The Centers for Medicare & Medicaid Services attribution methodology was recapitulated; and screening services were identified for breast, colorectal, and prostate cancer, implementing both sensitive and specific definitions of cancer screening. Adjusted difference-in-differences analyses were performed using linear regression to characterize changes in annual screening rates after ACO enrollment relative to contemporaneous changes in a non-ACO control group of Medicare beneficiaries. Results: Medicare beneficiaries attributed to ACO-enrolled providers had higher rates of breast, colorectal, and prostate cancer screening before enrollment. A 1.8% relative reduction in breast cancer screening was observed among women attributed to ACO providers (P