Rail expansion alone does not guarantee lower medical costs

Japan's transition to a super-aged society is intensifying pressure on healthcare and social security spending. In response, national policy has promoted "Compact Plus Network" planning, which encourages people to live near public transit and rely less on automobiles.

Sayana Wakisaka and Junior Associate Professor Haruka Kato's team at Osaka Metropolitan University's Graduate School of Human Life and Ecology, in collaboration with the Future Co-Creation Laboratory at Japan System Techniques Co., Ltd., examined whether opening a new station reduces medical costs. The researchers used a natural experiment created by the staggered opening of the Osaka-Higashi Line, which comprised of a southern section opened in 2008 and a northern section opened in 2019. By analyzing health insurance claims from the medical dataset REZULT, the team applied a Causal-Impact algorithm to estimate the causal effect of the 2019 station openings on regional health expenditure (RHE) per person among medically treated middle-aged adults. The analysis covered 4 years before and after the opening of JR-Awaji, Shirokitakoendori, JR-Noe, and Shigino stations, focusing on healthcare utilization within an 800-meter radius of each station.

At the railway-line level of the stations analyzed, the results revealed that the openings were not associated with a statistically significant reduction in RHE over 4 years. However, a clear difference emerged at the individual station level. Shigino Station showed an estimated cumulative reduction of approximately JPY 62,500.62 (approx. USD 562) per person over four years. Unlike the other stations, Shigino serves as a transfer hub connecting to the JR Gakkentoshi Line and the Osaka Metro Imazatosuji Line, providing stronger inter-network connectivity. This likely encourages more frequent use of transportation and walking, contributing to better health outcomes. Furthermore, this suggests that the healthcare cost impacts of station openings are highly place-dependent and influenced by local factors.

These findings reveal that opening new stations does not automatically generate healthcare savings across a corridor. However, when we look at stations individually, results suggest that connectivity and local context can shape whether a station opening translates into lower healthcare expenditure, offering practical clues for health-informed rail planning."

Haruka Kato, Junior Associate Professor, Osaka Metropolitan University's Graduate School of Human Life and Ecology

The findings were published in the Journal of Transport & Health.