Comparison of Populations Served in Hospital Service Areas With and Without Comprehensive Primary Care Plus Medical Homes

Importance Little is known about the types of primary care practices that have chosen to participate in the Comprehensive Primary Care Plus (CPC+) program or about how participation could affect disparities. Objective To describe practices that joined the CPC+ model and compare hospital service areas with and without CPC+ practices. Design, Setting, and Participants This comparative cross-sectional study identified 2647 CPC+ practices in round 1 (from January 1, 2017; round 1 is ongoing through 2021). Using IMS Health Care Organization Services data, ownership and characteristics of health systems and practices were extracted. Practices participating in the CPC+ program were compared with practices with similar proportions of primary care physicians (>85%) within the 14 regions designated as eligible to participate by the Centers for Medicare & Medicaid Services. Within eligible regions, hospital service areas with (n = 434) and without (n = 322) 1 or more CPC+ practice were compared. Characteristics compared included area-level population demographics (from the US Census Bureau), health system characteristics (from the IMS Health Care Organization Services), and use of health services by Medicare fee-for-service enrollees (Dartmouth Atlas). Main Outcomes and Measures Area-level characteristics of all eligible CPC+ regions, areas without a CPC+ practice, and areas with 1 or more CPC+ practices. Results Of 756 eligible service areas, 322 had no CPC+ practices and 434 had at least 1 CPC+ practice. Of 2647 CPC+ practices, 579 (21.9%) had 1 physician and 1791 (67.7%) had 2 to 10 physicians. In areas without CPC+ practices, the population had a lower median income ($43 197 [interquartile range, $42 170-$44 224] vs $57 206 [interquartile range, $55 470-$58 941]), higher mean share of households living in poverty (17.8% [95% CI, 17.2%-18.4%] vs 14.4% [95% CI, 13.9%-15.0%]), higher mean educational attainment of high school or less (52.7% [95% CI, 51.7%-53.6%] vs 43.1% [95% CI, 42.1%-44.2%]), higher mean proportion of disabled residents (17.7% [95% CI, 17.3%-18.2%] vs 14.2% [13.8%-14.6%]), higher mean participation in Medicare (21.9% [95% CI, 21.3%-22.4%] vs 18.8% [95% CI, 18.3%-19.1%]) and Medicaid (22.2% [95% CI, 21.5%-22.9%]) vs 18.5% [95% CI, 17.8%-19.2%]), and higher mean proportion of uninsured residents (12.4% [95% CI, 11.9%-12.9%] vs 10.3% [95% CI, 9.9%-10.7%]) ( P Conclusions and Relevance According to this study, although a diverse set of practices joined the CPC+ program, practices in areas characterized by patient populations with greater advantage were more likely to join, which may affect access to advanced primary care medical home models such as CPC+, by vulnerable populations.