Evaluation and optimization of emergency medical services accessibility based on real-world emergency calls in metropolitan China

Abstract Rapid access to emergency services in metropolitan areas is crucial for urban sustainability. In recent years, the concept of urban resilience has received increasing attention, with emergency medical services (EMS) coverage and accessibility emerging as a crucial component. Taking Shenzhen as an example, this study proposes a framework focusing on the EMS system planning. The demand of EMS isestimated by real-world ambulance dispatch data, and the supply is assessed based on the varying capacity of each EMS station. Based on real-world EMS demand and supply, this study first identifies areas with low EMS accessibility by a Nearest-neighbor Gaussian two-step floating catchment area (NN-Ga2SFCA) method. Taking existing medical institutions within low-EMS-accessibility areas as candidate EMS stations, this study introduces an optimized scheme for EMS stations distribution through the p-median model. Finally, it is found that the accessibility of the EMS in Shenzhen has significantly improved by making a comparative analysis before and after optimization. The framework offers a practical and meaningful procedure to EMS planning. This study can help urban policymakers formulate medical-related policies and serve as a benchmark for optimizing EMS in other megacities.