# Analyzing Disparity in Geographical Accessibility to Home Medical Care Using a Claims Database and Geographical Information System: Simulation Study

## TL;DR

This study uses a medical claims database and geographic analysis to show that rural areas in Japan have worse access to home medical care, and suggests increasing service availability could help.

## Contribution

The novel use of a comprehensive claims database and GIS to simulate and compare ideal vs. actual accessibility to home medical care in Japan.

## Key findings

- In actual conditions, some rural municipalities had median travel distances over 16 km and travel times exceeding 30 minutes.
- The largest improvements in travel time were observed in depopulated southern municipalities under an ideal scenario.
- Lower usage rates in rural areas suggest reduced access to home medical care services.

## Abstract

The demand for home medical care services has increased in aging societies. Therefore, allocating health care resources optimally to meet the needs of each community is essential. Geographical accessibility is an important factor affecting access to home medical care services; however, little research has been conducted on regional disparities in geographical accessibility.

This study aims to analyze the regional disparities in geographical accessibility to home medical care services using the Kokuho database (KDB), a comprehensive medical claims database for a prefecture in Japan.

This study included 39 municipalities in Nara Prefecture, Japan. Using a geographical information system, accessibility to home medical care services, that is, travel distance and time from hospitals and clinics to hypothetical patients, was analyzed in two scenarios: (1) an ideal scenario, where we assumed that all hospitals or clinics in Nara Prefecture provided those services and (2) an actual scenario, where hospitals or clinics in Nara Prefecture that actually provided home medical care services, identified from KDB data analysis, were used in the analysis. Hypothetical patients were randomly distributed on the geographical information system in accordance with the usage rates of home medical care services and with the distributions of the population aged ≥75 years. The usage rate by municipalities was aggregated from the analysis of KDB data of Nara Prefecture in FY2019.

The median travel distance was longer than 16 km, the reference limit value specified in the Japanese fee table, and the median travel time exceeded 30 min in certain rural municipalities in the southern part of Nara Prefecture, in the actual scenario, whereas the travel distance and time were improved in the ideal scenario. The differences in travel time between the ideal and actual scenarios were the largest in the depopulated municipalities in the southern part, such as Totsukawa (32.6 vs 5.8 min), Kawakami (30.1 vs 11.8 min), Kurotaki (21.3 vs 5.2 min), and Kamikitayama (20.7 vs 3.5 min). The usage rates were also lower in rural municipalities in the southern part.

The results revealed that geographical accessibility was lower in depopulated municipalities in the southern part, and the disparity could be partly solved in the ideal scenario, especially in that area, highlighting the necessity of increasing supply in the southern areas. KDB is a comprehensive database that includes medical claims information for home medical care patients and details of the provision of medical institutions, enabling geographical analysis that reflects actual health care usage.