Post-obligation physician retention among Jichi Medical University graduates in Okinawa prefecture, Japan: a descriptive comparative study of the Kyushu region

Abstract

Abstract Background Global strategies to address physician maldistribution include recruiting students with rural backgrounds, community-based training, bonded service, financial incentives, and personal and professional support. However, retention after obligatory service remains variable. Jichi Medical University (JMU) in Japan was established to address physician shortages in rural areas through a scholarship loan programme requiring graduates to complete nine years of service in their home prefectures. This study compares post-obligation retention patterns across the Kyushu prefectures and uses Okinawa as a context for secondary-source-based interpretation of why retention may differ across prefectures operating under a shared obligation framework. Methods This descriptive comparative study combined a cross-sectional analysis of retention data from eight Kyushu prefectures using the 2024 JMU Graduate Directory with a secondary-source-based contextual interpretation of Okinawa. Among 641 graduates who had completed medical school at least 10 years previously, retention was operationally defined as practising within the home prefecture on 1 July 2024. Quantitative analyses compared retention rates, prefectural capital concentration, and the ecological correlation between inhabited-island count and retention. The contextual interpretation drew on a review-derived framework linking geographical access conditions, institutional support and training arrangements, and sociocultural embeddedness to physician-retention factors described in previous reviews. Results Okinawa demonstrated the highest retention rate (84.2%) among the eight prefectures, exceeding Kagoshima (67.8%) and Saga (44.2%). In sensitivity analysis, excluding unknown workplace cases, Okinawa remained the highest at 90.1%, and the overall pattern was similar. No clear linear association was observed between inhabited-island count and retention. Descriptive comparison and secondary-source-based contextual interpretation identified three hypothesis-generating domains that may help interpret Okinawa’s pattern: (1) comprehensive structured training and support, (2) distributed healthcare infrastructure and placement arrangements, and (3) cultural cohesion characterised by communal reciprocity ( yuimaru ) and strong regional identity. Conclusions Okinawa’s comparatively high physician retention may be interpreted in relation to a combination of structured training and support systems, distributed healthcare infrastructure, and cultural cohesion. Because the contextual interpretation was based on secondary sources, these inferences should be regarded as hypothesis-generating rather than explanatory. Nevertheless, comparison across prefectures within a shared JMU obligation framework highlights how implementation context may be relevant to post-obligation retention and identifies priorities for future empirical research.