The Challenge of Adapting a Spatial Accessibility Indicator Developed for Primary Care to the Hemodialysis Context

Access to dialysis facilities greatly affects patients' quality of life and healthcare costs. Transportation alone represents 21% of dialysis-related expenses. Going beyond a simple focus on access, this study aimed to evaluate dialysis care accessibility in France by using a spatial analysis approach, offering insights for healthcare planning and resource allocation strategies.

We developed a novel spatial accessibility indicator based on an Enhanced Two-Step Floating Catchment Area (E2SFCA) method, incorporating custom distance-decay functions calibrated to actual patient travel patterns. The resulting value represents the number of available dialysis stations per individual within a population cluster. A value close to 1 indicates a balance between supply and demand with adequate geographic proximity, values <1 suggest insufficient availability or reduced accessibility, and values >1 indicate greater availability relative to local needs. The study analyzed data for all French chronic hemodialysis patients as of December 31, 2021, excluding those on home dialysis. Using hexagonal grid mapping and the Local Indicators of Spatial Association test, we identified spatial clusters and disparities in dialysis accessibility.

The median accessibility score across all modalities was 0.68 (interquartile range: 0.48-0.93) dialysis stations per patient in the facilities' catchment areas, increasing to 0.88 (0.66-1.14) in patient-occupied hexagons. Self-care units showed the highest alignment between supply and demand (median: 1.02, 0.74-1.34), and facility-based units exhibited lower overall accessibility (median: 0.62, 0.42-0.89). An east-west accessibility division emerged. Rural and mountainous areas consistently had lower accessibility scores than urban areas.

Our study poses a number of challenges, particularly in terms of defining supply and interpreting the results. Our E2SFCA method revealed substantial regional disparities and modality-specific patterns in dialysis accessibility across France. This approach is an exploratory planning tool to inform resource allocation decisions while addressing geographic inequities.