Declining Ambulance Offload Delays and Stabilised Emergency Department Length of Stay Post-COVID: An Interrupted Time Series Analysis

Objective: Ambulance offload delays and emergency department [ED] crowding worsened during COVID-19 and remain critical in Victoria, where <62 % of ambulances offload on time. Evidence on post-pandemic trends is limited. We analysed offload delays and ED length of stay [LOS] at a major Melbourne health service [Jan 2018-Aug 2024] across three periods: pre-COVID, during COVID and post-COVID, stratified by admission status. Methods: Monthly median offload times and ED LOS were examined using interrupted time-series models to detect level and slope changes. Results: Among 529 261 presentations, median offload times for non-admitted patients increased 12.7 min at the post-COVID transition then fell 0.62 min per month, ending below pre-COVID projections. Admitted patients showed a median 14.2 min increase and a 0.73 min per month decline. ED LOS median time rose post-COVID by 53.6 min for non-admitted and 124.8 min for admitted patients. Thereafter, non-admitted patient LOS declined, whereas admitted patient LOS remained persistently elevated and stabilised at a high level. Conclusions: Although ambulance offload delays have improved, now below pre-COVID counterfactual levels, emergency department length of stay remains elevated particularly for admitted patients. Targeted interventions such as dedicated offload staff, real-time bed management, and streamlined discharge pathways are needed to address persistent emergency department crowding.