Spatial analysis of accessibility to healthcare-related facilities in Tokyo Metropolis using geographic information systems

Geographic disparities in access to health services are a growing concern in Japan as population aging and decline increase care needs and as resources concentrate in dense urban cores. Focusing on Tokyo Metropolis as a large and internally heterogeneous urban region, we used geographic information systems to evaluate spatial proximity to healthcare-related facilities-pharmacies, hospitals, clinics, dental clinics, and elderly welfare facilities-together with public transportation infrastructure. For pedestrian access, we calculated population coverage from 400 m to 3200 m Euclidean buffers around each facility. For transportation-related proximity, we calculated the proportion of facilities located within 250 m to 3000 m buffers around public transportation features (bus stops, bus routes, and railway stations). Bus stop-based facility-transportation proximity was consistently high across facility types in both the 23 special wards and the Tama region, whereas railway-station proximity displayed larger spatial variation between areas. Interpreted as an indicator for walkable proximity rather than effective service access, these results highlight where transportation connectivity and facility locations align or diverge. These findings underscore the necessity for healthcare and urban planning strategies that integrate local characteristics with transportation infrastructure.