DOI: 10.1136/bmjopen-2026-117407 ISSN: 2044-6055

Geographical and climatic factors driving regional variation in medical centres for dementia in Japan: a nationwide geocomputational analysis

Yoshihiko Baba, Shuji Tsuda, Kae Ito, Shuichi Awata

Objectives

Japan’s dementia policies have mandated establishing at least one medical centre for dementia (MCD) in each secondary healthcare area (SHA) and ensure equitable access to specialised dementia care services across regions. This study aimed to identify the geographical and climatic characteristics of MCDs and examine geographical accessibility to MCDs, and to clarify the geographical characteristics of SHAs in which MCDs have not been established, despite the policy that an MCD should be established in each SHA.

Design

A geocomputational analysis using publicly available geographical datasets

Methods

We conducted a geocomputational overlay analysis of the spatial distribution of the three types of MCDs across areas with heavy snowfall, mountainous areas, agricultural areas, peninsulas and remote islands. We then reviewed prefectural development policies and municipal dementia care pathway documents in SHAs without MCDs. Finally, catchment analysis was performed to estimate geographical accessibility to the nearest MCD in areas where SHAs without an MCD were concentrated. We used the datasets of municipalities, secondary healthcare areas, heavy snowfall, mountainous areas, agricultural areas, peninsulas and remote islands, provided by the Ministry of Land, Infrastructure, Transport and Tourism and the dataset of MCDs provided by the Ministry of Health, Labour and Welfare.

Results

Overall, 509 MCDs were identified nationwide: 109 (19.8%) in areas of heavy or extremely heavy snowfall, 12 (2.4%) in mountainous areas, 72 (14.1%) in agricultural areas, 29 (5.7%) on peninsulas and 11 (2.2%) on remote islands. Of the 344 SHAs, 18 (5.2%) did not have an MCD, encompassing 105 municipalities. The MCDs comprise three categories: 21 core, 388 regional and 100 affiliated centres. While only one core centre (4.8%) was located in an agricultural area, 46 regional centres (11.9%) and 25 affiliated centres (25.0%) were located in agricultural areas. dementia care pathways analysis revealed that these municipalities either did not designate any MCDs (41%), designated MCDs in adjacent municipalities (21%) or listed all MCDs within the prefecture (36%). Municipalities that did not designate an MCD in their dementia care pathways were primarily located in geographically or climatically disadvantaged areas, including heavy-snowfall regions and peninsulas. Catchment area analysis using 30 km driving isochrone from the nearest MCD revealed that mountainous terrain, heavy snowfall and the presence of a large lake limited catchment coverage in municipalities that did not designate an MCD in their dementia care pathways.

Conclusions

While the nationwide expansion of MCDs has largely achieved regional coverage, gaps remain in geographically disadvantaged areas where SHAs lack an MCD. Future dementia care planning should consider geographical accessibility in addition to administrative coverage to ensure equitable access to specialised dementia services.

More from our Archive