Equity and spatial effects of hospital accessibility in Sichuan Province: evidence from GA2SFCA-based data

Introduction Healthcare accessibility lies at the core of health equity; however, provincial-scale evidence on its spatial inequality and cross-county interactions remains limited, particularly in western China. Methods We used a 2020 national 1 km grid accessibility dataset and aggregated scores to 183 county-level units. Equity was assessed using the coefficient of variation and Palma ratio across prefecture, county, and grid scales. Subsequently, we analyzed the spatial effects of accessibility using Moran’s index and a Spatial Durbin Model (SDM). Results Accessibility exhibited a significant east-high, west-low gradient distribution. Inequality intensified with finer spatial units: the coefficient of variation increased from 42.16% at the prefecture level to 77.23% at the county level, and reached 148.28% at the grid level. Significant positive spatial autocorrelation confirmed clustering patterns, and the SDM spatial lag parameter was significantly positive. Direct effects showed that GDP and road density enhanced county-level accessibility, while fiscal expenditure and altitude exerted negative effects; population size had no significant direct effect. Indirect effects presented a different picture: population size had a negative spillover on neighboring areas, whereas fiscal expenditure generated positive cross-county spillovers. Conclusion These findings indicate that healthcare planning in western China cannot rely solely on administrative boundaries. To reduce accessibility disparities, policies should prioritize differentiated resource allocation, coordinate transport and medical infrastructure planning, and refine fiscal transfer mechanisms to leverage positive spatial spillovers.