The Diseconomies of Queue Pooling: An Empirical Investigation of Emergency Department Length of Stay
Executive Summary — Improving efficiency and customer experience are key objectives for managers of service organizations including hospitals. In this paper, the authors investigate queue management, a key operational decision, in the setting of a hospital emergency department. Specifically, they explore the impact on throughput time depending on whether an emergency department uses a pooled queuing system (in which a physician is assigned to a patient once the patient is placed in an emergency department bed) or a dedicated queuing system (in which physicians are assigned to specific patients at the point of triage). The authors measured throughput time based on individual patients' length of stay in the emergency department, starting with arrival to the emergency department and ending with a bed request for admission to the hospital or the discharge of a patient to home or to an outside facility. The findings show that, on average, the use of a dedicated queuing system decreased patients' lengths of stay by 10 percent. This represented a 32-minute reduction in length of stay—a meaningful time-savings for the emergency department and patients alike. The authors argue that physicians in the dedicated queuing system had both the incentive and ability to make sure their patients' care progressed efficiently, so that patients in the waiting room could be treated sooner than they otherwise would have. Key concepts include:
- This study tests the impact of a queuing system structure on the throughput time of patients in an emergency department that had recently switched from a pooled queuing system to a dedicated queuing system.
- Patients experienced faster throughput times when physicians were working in a dedicated queuing system as opposed to a pooled queuing system.
- The benefits of a dedicated queuing system may be due to greater visibility into one's workload and the increased ability for physicians to manage patient flow.
We conduct an empirical investigation of the impact of two different queue management systems on throughput times. Using an Emergency Department's (ED) patient-level data (N = 231,081) from 2007 to 2010, we find that patients' lengths of stay (LOS) were longer when physicians were assigned patients under a pooled queuing system, compared to when each physician operated under a dedicated queuing system. The dedicated queuing system resulted in a 10 percent decrease in LOS-a 32-minute reduction in LOS for an average patient of medium severity in this ED. We propose that the dedicated queuing system yielded shorter throughput times because it provided physicians with greater ability and incentive to manage their patients' flow through the ED from arrival to discharge. Consistent with social loafing theory, our analysis shows that patients were treated and discharged at a faster rate in the dedicated queuing system than in the pooled queuing system. We conduct additional analyses to rule out alternate explanations, such as stinting on care and decreased quality of care. Our paper has implications for health care organizations and others seeking to reduce throughput time, resource utilization, and costs.