Geographical distributions of physicians in Japan and US: Impact of healthcare system on physician dispersal pattern

Objectives: This study examined the effect of increased physician numbers overall on the geographic distribution of the physicians in Japan and the US.

Methods: Equity of physician distribution with reference to community population and community income was evaluated in all municipalities in Japan, and all counties in the US.

Results: Between 1980 and 2005, Japan and the US experienced a 55% and 47% increase in the number of physicians per unit population, respectively. The Gini coefficients against population were at similar values between Japan and the US, and have been almost unchanged in the past 25 years in both countries. The Gini coefficient against income in the US was lower than the coefficient in Japan, and the US value has decreased since 1980. Correlation between physician-to-population ratio and per capita income among the communities was stronger in the US than in Japan and has increasingly been strengthened during the period examined.

Conclusions: In spite of constant growth of physician numbers, physicians do not diffuse according to population distribution in both countries. Rather, US physicians seem to diffuse according to income distribution. In order to reverse the continuing maldistribution of physicians, political intervention is required in both countries.