2025 年 8 巻 2 号 p. 506-516
Introduction: Because regional physician maldistribution is considered a potential contributor to disparities in healthcare outcomes, several countries regulate the number of physicians and specialists per region to ameliorate health disparities. However, the association between regional physician maldistribution and specific outcomes, such as out-of-hospital cardiac arrest (OHCA) at the regional level, remains unclear. This study aims to evaluate the association between regional physician and specialist maldistribution and OHCA outcomes.
Methods: This ecological study used 12 years of longitudinal public open datasets in Japan. We examined the disparity trends of indices of physician and specialist (emergency physicians, cardiologists, and cardiac surgeons) distribution using the Gini index. We also examined the physician uneven distribution index, a newly introduced policy index incorporating local demand and supply of medical services. Next, we analyzed the association between these distributions and OHCA-related outcomes (30-day survival rate and 30-day favorable neurological outcome).
Results: The overall number of physicians and each specialist steadily increased throughout all regions and the observation period, but the trends in the regional distribution of specialists for each region were not always synchronized with the distribution of overall physicians. Although the disparity within each index has gradually decreased, the disparity of specialists remained high compared with overall physicians. Moreover, regional physician distributions, which showed the lowest level of disparity across regions, were consistently associated with OHCA-related outcomes, whereas the regional disparity of specialists, which consistently exhibited a higher level of disparity, was not associated with the outcomes.
Conclusions: Paradoxically, the unevenly distributed specialist distribution indices did not reflect their relevant outcomes, despite their direct involvement in the specific outcomes. Therefore, our findings call into question the validity of policies aimed at correcting the total number of physicians without considering the impact of specialists on healthcare outcomes.