Simulation models for patient flow in an emergency department

Abstract

The emergency departments are complex systems with many variables, it is one of the most problematic and challenging services in the health system, as there is a constant increase in demand and an insufficient structure. The simulation can help health managers to analyze the causes, make decisions and propose improvements without interrupting the routine of the process. However, mainly in Brazil, simulation methods in the health sector are little explored. The literature shows the existence of three growing simulation methods that can operationally assess the emergency department. The discrete event simulation (DES), which models the process flow, the agent-based simulation (ABS), which models the behavior and interaction of patients, doctors and technical staff, and the hybrid method that integrates the two previous methods and allows evaluate flow and behavior in the same model. This research assesses which model is most appropriate to simulate the patients’ flow in an emergency department. The evaluation considers the criteria of time, cost, knowledge and need for data. Based on the theoretical background and data collected in a health institution in the state of Rio Grande do Sul, Brazil, a conceptual model was developed and four computer simulation models were devised for the emergency department. One model in DES, one model in ABS, and two hybrid models, one integrating the patient in ABS and the resources in DES, and another model integrating the patients in DES and the resources in ABS. The results of the simulations showed adherence compared to the real data. To achieve this research, the four models were compared in relation to time, cost, knowledge and data. When analyzing the simulation categories, inputs, outputs, development, and results of the models, an orientation framework was built on which model is most appropriate for each manager’s need. This framework helps managers and researchers to choose the most appropriate simulation model to apply in their emergency department, considering the advantages and disadvantages of each method.