Approaches to quantifying spatial accessibility using the example of inpatient hospices in Germany

Background. Spatial access is an important indicator to assess the quality of healthcare services and the healthcare situation. Accessibility and availability are central components of this indicator. Using inpatient hospices as an example of specialist palliative care in Germany, this study will present various indicators for operationalizing spatial access, identify regional differences, and discuss possible differences in the results caused by methodological characteristics. Methods. Locations of inpatient hospices were identified using a freely accessible web-based self-disclosure database, supplemented by lists from regional associations and own research. Spatial access was examined using provider-to-population ratios based on district level and network-based travel time Further, two variants of the floating catchment area methods (FCA), the Two-Step Floating Catchment Area (2SFCA) and Enhanced Two-Step Floating Catchment Area (E2SFCA) were applied. The analyses used geocoded locations, hospice bed capacities, population data, and road network data. Results. 295 inpatient hospices were identified. 211 of the 401 districts have at least one hospice, resulting in an availability of 36.4 beds per 1 million inhabitants for all of Germany. 90.3% of the population can reach a hospice within 30 minutes by motorized private transport. The results of the FCA methods show a heterogeneous pattern in the spatial accessibility index (SPAI _i ), with the application of the slow and sharp distance decay function having different effects. Using the 2SFCA method results in uniform accessibility within the catchment areas of the hospices. While the E2SFCA method with a slow distance decay function generates smoother transition zones within the catchment areas, the sharp distance decay function induces higher spatial differentiation, particularly in rural areas, where accessibility declines sharply with distance. Conclusions. The results indicate that inpatient hospices in Germany are very accessible. However, the chosen method significantly influences the results. Indicators such as provider-to-population ratios and network-based travel time can provide a basic analysis of the care situation due to their ease of interpretation. FCA methods are more complex but also more meaningful due to their joint consideration of availability and accessibility.