Planning model of resource utilization in an academic pediatric emergency department

This study describes a field observation study and use of simulation to quantify the effect of patient arrival rate and physician practices on physician idle time and patient wait time. The observation study measured actual service (diagnosis, therapy, and charting) times for 126 patients. Subsequently, a FORTRAN simulation model examined effects of physician practices and patient arrival rate on physician utilization and patient wait time. Observations were taken in the emergency department of an urban, university-affiliated pediatric teaching hospital. Although times for initial diagnostic evaluation (diagnosis), therapy, and charting averaged 13.3, 13.8, and 11.6 minutes, respectively, maximum patient visits approached six hours. The simulation model showed that, during times of frequent patient arrivals, maximum patient wait times increased greatly. Additionally, the model predicted that physician idle time persists even during periods of frequent patient arrivals and long maximum visit times. Emergency department (ED) senior staff (fellows and attendings) often begin treating new patients when current patients leave for tests external to the ED. This practice increases physician utilization and makes more physician capacity available, but it may lead to small additional patient waits if the physician is treating another patient when the first patient returns from the external test before their original physician becomes free. On the other hand, during periods of high patient arrivals, increased physician utilization and reduced idle time result in reduced average and expected maximum patient visit times. Unfortunately the variability in visit times increased. A very small percentage of patients wait longer, owing to additional waits incurred upon returning from external testing. Overall, most patients benefit from shorter visits. Finally, the study suggested maximum rather than average wait time be considered as a measure of emergency department capacity and quality of service provided. Although average wait times seemed reasonable, maximum wait times were at times quite long and could impact both physician's and patient's perceptions of service quality.