Measuring maternal healthcare accessibility in Florida by a data-driven extension of V2SFCA

Maternal healthcare accessibility is a key determinant of maternal and newborn outcomes, yet the United States continues to experience disproportionately high maternal mortality rates compared with other high-income countries. Efforts to address this problem are hampered by substantial spatial disparities, especially in large states like Florida. Existing methodologies for evaluating healthcare access, such as the widely used Generalized Two-Step Floating Catchment Area (G2SFCA) method, may not accurately capture real-world circumstances because they often rely on assumed, uniform parameters that overlook contextual heterogeneity in travel behavior. However, maternal patients in different geographies experience drastically different transportation barriers and varying tolerance for distance and travel times, underscoring the need for more granular, area-specific modeling. This study proposes a data-driven Variable Catchment 2SFCA (V2SFCA) framework to estimate maternal healthcare accessibility across Florida. Leveraging observed patient flow data, we employed gravity models to empirically calibrate distance decay functions and separately defined catchment thresholds specific to each area type. These data-driven, area-specific parameters enable the framework to more accurately reflect behavioral heterogeneity in maternal healthcare utilization. Applied to Florida, the model reveals substantial accessibility disparities across the four area types, including metropolitan, micropolitan, small town, and rural. It also demonstrates improved behavioral realism compared with conventional approaches, offering actionable insights for equitable maternal care planning and resource allocation.