Identifying trade-offs in equity and efficiency for simultaneously optimizing location and multipriority dispatch of ambulances

摘要

The role of emergency medical service (EMS) systems is to provide acute care and possibly transportation to health care facilities to patients experiencing medical emergencies. Since EMS is a public service, it is natural for the community to expect equitable service from these systems; however, there is not a unique agreement on how to measure equity. Most EMS planning literature focuses solely on measures of efficiency, such as minimizing average response time. Solutions based on optimizing efficiency measures alone can be unacceptable when they are achieved at the expense of some players. Such trade-offs can be more crucial when it comes to high-priority emergencies.We provide a multicriteria optimization approach aimed at identifying good solutions for several equity and efficiency measures together, based on a joint modeling approach for location and dispatching policy decisions, while considering multiple levels of call priority. We apply our approach to a real-world data set. We show that the joint approach provides better solutions than using the common assignment of the closest available ambulance, in particular for the equity criteria. We quantify the trade-offs between different performance measures, and provide Pareto-efficient solutions. The proposed joint optimization approach can be used to gain insight about the implicit balance between common efficiency measures and discussed equity criteria, hence providing better information to policy makers and EMS system administrators.