Links to research manuscripts may be found below.

Feizi, A., Tucker, A., Berry Jaeker, J., & Baker, W. (2021). To Batch or Not to Batch? Impact of Admission Batching on Emergency Department Boarding Time and Physician Productivity, Under 3rd revision at Operations Research [link SSRN]

    • Abstract: We study the behavior of batching by discretionary workers in the first stage of a two-tier queuing system, and explore the trade-off it causes between their productivity and second stage wait times. Specifically, we focus on the behavior of batching admissions by emergency department (ED) physicians. Using data from a large hospital, we show that the probability of batching admissions is increasing in the hour of an ED physician's shift, and that batched patients experience a 4.6% longer delay from hospital admission to receiving an inpatient bed. Using a mediation analysis we show that this effect is partially due to the increase in the coefficient of variation of inpatient bed-requests caused by batching. However, we also find that batching admissions is associated with an average of 11.4% more patients seen in a shift, and a 2.5 minute reduction a physician's average throughput time. An important implication of our work is that workers may induce delays in downstream stages, caused by practices that increase their productivity.

Feizi, A., Baker, W. (2021). Limits of Capacity Flexibility: Impact of Hallway Placement on Patient Flow and Quality of Care in the Emergency Department [link SSRN]

    • Abstract: A common practice in busy emergency departments (EDs) is to admit patients from the waiting area to hallway beds as the regular beds fill up. Using data from a large ED, we first perform a causal analysis to quantify the impact of hallway placement on wait times and quality of care, defined by ED length of stay (LOS) and likelihood of adverse outcomes. We find that patients placed in a hallway bed experience a 20 minute (28%) lower door-to-doctor time (delay from arrival to first being seen by a caregiver). This reduction is 50 minutes (76%) for low-acuity patients who are treated in a fast-track area, which is isolated from the rest of the ED. However, hallway patients experience an average of 25 minutes (16.1%) and 18 minutes (9.2%) longer disposition time, and LOS, respectively. Moreover, we find that hallway patients are 20% more likely to experience an adverse outcome. Next, we perform a counterfactual analysis using a data-driven simulation of the ED to find better hallway usage policies. We find that a pooling policy, where hallway beds are used only if all regular beds are full, has the greatest impact on reducing wait times albeit at the cost of slightly higher hallway utilization. Also, too little or too much wait tolerance for rooming patients may result in under- or over-utilization of the hallway space, both of which are detrimental to ED average throughput times and wait times.