Primary Care Physician Workforce and Medicare Beneficiaries’ Health Outcomes

Study Questions:

Is there a positive relationship between the adult primary care physician workforce and individual patient outcomes?


This was a cross-sectional analysis of the outcomes of a 2007 20% sample of fee-for-service Medicare beneficiaries ages 65 years or older (n = 5,132,936), which used two measures of adult primary care physicians (general internists and family physicians) across Primary Care Service Areas (n = 6,542): 1) American Medical Association (AMA) Masterfile nonfederal, office-based physicians per total population, and 2) office-based primary care clinical full-time equivalents (FTEs) per Medicare beneficiary derived from Medicare claims.


Marked variation was observed in the primary care physician workforce across areas, but low correlation was observed between the two primary care workforce measures (Spearman r = 0.056; p < 001). Compared with areas with the lowest quintile of primary care physician measure using AMA Masterfile counts, beneficiaries in the highest quintile had fewer ambulatory care sensitive condition hospitalizations (74.90 vs. 79.61 per 1,000 beneficiaries; relative rate [RR], 0.94; 95% confidence interval [CI], 0.93-0.95), lower mortality (5.38 vs. 5.47 per 100 beneficiaries; RR, 0.98; 95% CI, 0.97-0.997), and no significant difference in total Medicare spending ($8,722 vs. $8,765 per beneficiary; RR, 1.00; 95% CI, 0.99-1.00). Beneficiaries residing in areas with the highest quintile of primary care clinician FTEs compared with those in the lowest quintile had lower mortality (5.19 vs. 5.49 per 100 beneficiaries; RR, 0.95; 95% CI, 0.93-0.96), fewer ambulatory care sensitive condition hospitalizations (72.53 vs. 79.48 per 1,000 beneficiaries; RR, 0.91; 95% CI, 0.90-0.92), and higher overall Medicare spending ($8,857 vs. $8,769 per beneficiary; RR, 1.01; 95% CI, 1.004-1.02).


The authors concluded that a higher level of primary care physician workforce, particularly with an FTE measure that may more accurately reflect ambulatory primary care, was generally associated with favorable patient outcomes.


A US health care policy that increases the number of persons insured will require a dramatic increase in primary care providers, particularly in rural areas. There has been a proliferation of medical schools to meet the need. It remains to be seen whether graduates will be attracted to primary care training.

Keywords: Physicians, Primary Care, Hospitalization, Primary Health Care, United States

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