Population aging and physician maldistribution: A longitudinal study in Japan

Background: Over the past two decades, population aging and the introduction of the new postgraduate medical education program in 2004 have impacted on the geographic maldistribution of physicians in Japan. The purpose of this study was to evaluate recent changes in physician distribution across municipalities from 1996 to 2012 using Gini coefficients and to clarify the impact of the new medical education program on physician distribution. Methods: We extracted the number of physicians classified by type of medical institution and municipal bodies. Gini coefficients were calculated using both population and demand for medical services. We calculated the contribution ratio (CR) of maldistribution within each type of medical institution to the whole maldistribution using Rao’s method. In addition, we calculated the incremental difference in Gini coefficients between 2002 and 2010, and calculated the CR of the incremental Gini coefficient difference for each medical institution type using Seki’s method. Results: Both Gini coefficients decreased from 1996 to 2002, and increased after 2006. The CR of other hospitals increased from 2004. The incremental difference in the Gini coefficient using demand between 2002 and 2010 was 0.012, and the CR of each type of medical institution was -25.1% (university hospitals), 131.0% (other hospitals) and -5.9% (clinics). Conclusions: Our analysis showed that the geographic maldistribution of physicians has worsened since the introduction of the new postgraduate medical education program, and the CR of maldistribution in other hospitals was high. Our study suggested that new medical resource distribution policies should be discussed to improve maldistribution.