Limits of Capacity Flexibility : Impact of Hallway Placement on Patient Flow and Quality of Care in the Emergency Department

A common surge-capacity policy in busy emergency departments (EDs) is to admit patients from the waiting area to hallway beds as the regular beds fill up. Despite its prevalence, the decision on who to place in a hallway bed, and when, is mostly on an ad-hoc basis and there are no well-defined policies in place. 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, as defined by room-to-departure (R2D) time and likelihood of adverse outcomes. We find that patients placed in a hallway bed experience a 20 minute (28%) lower door-to-doctor time. 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 R2D time, respectively. Moreover, we find that hallway patients are 20% more likely to experience an adverse outcome. Next, we perform a counterfactual analysisusing 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, significantly reduces wait times, albeit at the cost of a 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 overall ED length of stay (LOS) and wait times