Optimal dispatching strategies for emergency vehicles to increase patient survivability

A major focus of emergency medical service (EMS) systems is to save lives and to minimise the effect of an emergency health incident. The objective of this research is to determine how to optimally dispatch paramedic units to emergency calls to maximise patients' survivability. We formulate the problem as Markov decision process to obtain the optimal dispatching policies. These dispatching policies are developed incorporating the degree of the urgency of the call. The optimal policy provides an ordered preference (priority) list of ambulances to dispatch. The performance of the proposed dispatching rules is evaluated in terms of patients' survivability rather than measuring the response time thresholds, as survival probability more directly mirrors patient outcomes. Computational examples show that dispatching the closest vehicle is not always optimal and that dispatching vehicles considering the priority of the call leads to an increase in the average survival probability of patients.