The geographic distribution of physicians revisited

Abstract

Context: While there is debate over whether the U.S. is training too many physicians, many seem to agree that physicians are geographically maldistributed, with too few in rural areas.

Objective: Official definitions of shortage areas assume the market for physician services is based on county boundaries. We wished to ascertain how the picture of a possible shortage changes using alternative measures of geographic access. We measure geographic access by the number of full-time equivalent physicians serving a community divided by the expected number of patients (possibly both from within the community and outside) receiving care from those physicians. Moreover, we wished to determine how the geographic distribution of physicians had changed since previous studies, in light of the large increase in physician numbers.

Design: Cross-sectional data analyses of alternative measures of geographic access to physicians in 23 states with low physician-population ratios.

Results: Between 1979 and 1999, the number of physicians doubled in the sample states. Although most specialties experienced greater diffusion everywhere, smaller specialties had not yet diffused to the smallest towns. Multiple measures of geographic access, including physician-to-population ratios, average distance traveled to the nearest physician, and projected average caseload per physician, confirm that residents of metropolitan areas have better geographic access to physicians. Physician-to-population ratios exhibit the largest degree of geographic disparity, but ratios in rural counties adjacent to metropolitan areas are smaller than in those not adjacent to metropolitan areas. Distance-traveled and caseload models that allow patients to cross county lines show less disparity and indicate that residents of isolated rural counties have less access than those living in counties adjacent to metropolitan areas.

Conclusion: Geographic access to physicians has continued to improve over the past two decades, although some smaller specialties have not diffused to the most rural areas. While substantial variation in the supply of physicians across communities remains, current measures of geographic access to physicians overstate the extent of maldistribution and yield an incorrect ranking of areas according to geographic accessibility of physicians.