Primary Care Physicians' Links to Other Physicians Through Medicare Patients

Policy-makers and insurers are searching for strategies to improve care coordination and reinvigorate primary care as a critical component of reforming the U.S. health care system. As Medicare and private health plans experiment with extra payments to primary care physicians to coordinate care—for example, through medical homes—this study's findings suggest that substantial delivery system reforms may be needed to make such models work.

The study is based on the Center for Studying Health System Change's nationally representative 2004–05 Community Tracking Study Physician Survey, which collected information from 6,600 practicing physicians and Medicare claims information on beneficiaries these physicians treated in 2005. Data on physicians and patients were linked with the use of the physicians' unique provider identification number; with a total of 2,284 primary care physicians and 576,875 elderly Medicare patients included in the study.  Each primary care physician in the study treated an average of 264 unique Medicare fee-for-service patients.

Key Findings:

  • For every 100 Medicare patients treated, each primary care physician would typically have to communicate with 99 physicians in 53 practices to coordinate care.
  • Physicians who treated patients with more chronic conditions typically had to interact with 134 physicians in 62 practices for every 100 Medicare patients.
  • Physicians working in solo or two-person practices had more peers than physicians in larger group practices and institutional work settings.
  • The number of peers varied with geographic region, practice type, and reliance on Medicaid revenues.

The study's lead author Pham states, "logistical challenges to care coordination are daunting given the fragmentation of care and the large number of peers that physicians must interact with when treating Medicare patients."