Mode of Arrival Aware Models for Forecasting Flow of Patient and Length of Stay in Emergency Departments

Aim: Flow of patients to emergency departments (EDs) and their stays in EDs (ED-LOS) depend significantly on their arrival modes. In this study, developing effective models for forecasting patient flow and LOS in EDs by considering arrival modes is aimed to lead better planning of ED operations.
Materials and Methods: In this study, by categorizing mode of arrival into two, self-arrived in and by ambulance, autoregressive integrative moving average (ARIMA) models are applied for forecasting four time series: daily number of patients self arrived/arrived by an ambulance and average LOS of patients self-arrived/ arrived by an ambulance. The models are validated with real-life data received from a large-scaled urban ED in Izmir, Turkey.
Results: While seasonal ARIMA is proper for forecasting daily number of patients on both modes, non-seasonal models are proper for forecasting average LOS. The mean absolute percentage errors (MAPE) for the models of four time series are respectively as 5.432%, 13.085%, 9.955% and 10.984%. Thus, daily arrivals to EDs show seasonality patterns.
Conclusion: By emphasizing the impact of mode of arrival in ED context, this study can be used to aid strategic decision making in EDs for capacity planning to enable efficient use of ED resources.