Discrete event simulation to understand ambulance performance and improvement strategies

Ambulance handover problems and deteriorating response times have been dominating the Urgent & Emergency Care space over the past years. The NHS England UEC recovery plan published in 2023 set out ambitions which include improved response times over the following two years. Interventions are being considered nationally and by local systems to achieve these ambitions. This includes improving in-hospital patient flow, increasing the ambulance fleet, reducing unnecessary conveyances and increasing clinical assessment of calls. This work aims to help build a model that can represent the non-linear ambulance system and assess the effect of interventions on handover delays and response times. We use discrete event simulation to model the ambulance system. The model takes into account on-duty supply profiles, demand by category and models of care, job cycle time components and the emergency department status. We validate and provide sensitivity analysis for such a model.