Cardiologists are joining larger practices over time as health care markets change and emphasis on alternative payment models (APMs) increases, according to a study published July 27 in the Journal of the American College of Cardiology.

Jose F. Figueroa, MD, MPH, et al., looked at whether cardiologists joined larger practices between 2013 and 2017 and at physician-level, community-level and supply-side factors associated with practice consolidation. Researchers used the Centers for Medicare and Medicaid Services (CMS) Physician Compare website to analyze physician-level data, looking at both general cardiologists and subspecialists, such as interventional cardiologists. Market-level factors were assessed using the hospital referral region (HRR), a geographic area representing markets, and the Herfindahl-Hirschman index (HHI), which measures concentration and competitiveness. Community-level characteristics were collected from the American Community Survey.

The number of U.S. practices with at least one cardiologist decreased from 8,642 in 2013 to 7,709 in 2017. Practices in rural areas had an average of 2.05 cardiologists in 2013 vs. 2.20 in 2017. In urban areas, the average number of cardiologists per practice increased from 3.67 in 2013 to 4.38 in 2017. The proportion of cardiologists in practices with one or two cardiologists decreased during the study period (20.2% in 2013 vs. 16.1% in 2017), as did the proportion in practices with three to five cardiologists (14% vs. 10.9%), and six to 10 cardiologists (16.9% vs. 14%). During the same period, there were increases in the proportion of cardiologists in practices with 25 to 49 cardiologists (16.3% vs. 19.1%) and in practices with 50 or more cardiologists (9.7% vs. 16.7%).

Increased concentration in hospital markets was associated with larger practices, with a 0.1 increase in hospital-level HHI associated with an average increase of 0.34 cardiologists per practice (95% confidence interval, 0.10 – 0.58; p = 0.005). No other supply factors were associated with increased practice size. In addition, the researchers found no association between changes in practice size and community-level or physician-level factors.

According to the researchers, cardiologists may be joining larger practices in response to market changes, including hospital consolidation and insurer consolidation. The rise of APMs, such as bundled payments and accountable care organizations, also may be contributing. The association between higher market concentration and greater growth in practice size "suggests cardiologists may be responding to market-level forces," the researchers conclude.

Keywords: Accountable Care Organizations, Centers for Medicare and Medicaid Services, U.S., Insurance Carriers, Health Care Sector, Medicaid, Medicare, Physicians, Hospitals, ACC Advocacy

< Back to Listings