LAUSR

Ensuring adequate public transport-based accessibility to health facilities in different regions is a major concern of social equity and public health for government. However, the imbalanced spatial distribution of health facilities may lead to an inaccurate evaluation of the accessibility, which is shaped by both land use and transportation. To address this problem, this study proposed a new approach to evaluate the adequacy of public transport-based accessibility to health facilities considering the spatial heterogeneity. First, we obtained the spatial distribution of health facilities based on POI data, calculated the population centroids of census tract-based mobile phone positioning data, and estimated travel times from population centroids to every health facility based on web map services. Second, the public transport-based accessibility to health facilities was measured by the isochrone approach. Then, the spatial heterogeneity of the health facilities was quantified by a spatial proximity index based on the gravity model. At last, a benchmark curve of accessibility vs. spatial proximity was established to evaluate the public transport-based accessibility to health facilities in different areas with spatial heterogeneity. A case study of 218 census tracts in Shanghai was conducted to verify this method. Consequently, we successfully identified the census tracts where the public transport-based accessibility to health facilities is insufficient. It shows that even some census tracts within the central city areas are still short of public transport-based accessibility to health facilities, whereas some tracts in the urban periphery may have adequate public transport-based accessibility even though there are limited health facilities nearby.