Discrete-event simulation and design of experiments to study ambulatory patient waiting time in an emergency department

Despite major investments in healthcare, access to front line health services (family doctors, walk-in clinics) is still difficult. If front line healthcare services remain insufficient, emergency departments will have to offer non-urgent patients appropriate services. More than half of emergency patients are ambulatory patients and their medical condition is not usually as serious as for patients on stretchers (Thibeault, 2014). This paper is devoted to the analysis of ambulatory patient length of stay in an emergency department of a hospital in the province of Quebec. The average length of stay for ambulatory patients in that hospital is slightly more than 7?hours which exceeds the average 4?hours observed for all emergency departments in Quebec. To identify the factors and their interactions affecting the performance of the hospital emergency, measured by the average length of stay for ambulatory patients, experimental design and discrete-event simulation were used. This research aims at verifying how nurses can contribute to reduce emergency department overcrowding. Our results show that giving more responsibility to nurses (collective prescriptions, review patients) reduce greatly the average patient length of stay with less financial effort than adding new doctors. This allows doctors to focus on the more acute patients.