Geographic distribution of family physicians in Japan and the USA: a cross-sectional comparative study.

Introduction: Solutions for geographic maldistribution of physicians is challenging around the world, but primary care specialists are expected to resolve this issue. This study compares the geographic distribution of family physicians in Japan and the USA, both of which are developed countries without a major system for physician allocation by the public sector; however, the two countries differ greatly in the maturity of family medicine (ie length of its history as part of the healthcare system and the population of qualified family medicine experts).

Methods: This cross-sectional comparative study used publicly available online databases for Japan in 2018 and 2017 in the USA. The municipalities in Japan and counties in the USA were divided into quintile groups according to population density. The number of family physicians per unit population in each group of areas was calculated, and was evaluated with a residual analysis. The geographic distribution of all physicians in Japan was simulated assuming that the proportion of family physicians among all physicians in Japan (0.16%) was increased to match that in the USA (11.8%).

Results: Of 320 084 physicians in Japan and 899 244 in the USA, 519 (77.2%) family physicians in Japan and 105 999 (100%) in the USA were included. The distribution of family physicians in Japan was noticeably shifted to areas with the lowest population density. In contrast, family physicians in the USA were distributed equally across areas. The distribution of physicians of other specialties (general internists, pediatricians, surgeons and obstetricians/gynecologists) was shifted heavily to areas with the highest population densities in both countries. The simulation analysis showed the geographic maldistribution of the total number of physicians improved substantially if the proportion of family physicians in Japan is increased to match that in the USA.

Conclusion: The distribution of family physicians is more equitable than that of other medical specialists; however, an immature family medicine system can lead to an aggregation of family physicians in rural areas. This aggregation supports equity due to the broader scope of practice required by family physicians in rural areas. In countries where family medicine has not yet matured as a specialty, provided that the equitable aggregation of family physicians in rural areas can be maintained, increasing the number of family physicians as a proportion of the total number of physicians may improve the geographic maldistribution of the total number of physicians.