Does What Happens in the ED Stay in the ED? The Effects of Emergency Department Physician Workload on Post-ED Care Use

Abstract

Problem Definition: We study the effects of emergency department (ED) physician workload on healthcare system utilization after the patient leaves the ED. Further, we explore the mediation effects of care intensity in the ED on post-ED care use. Relevance: ED crowding has been a persistent concern in the U.S. healthcare system. As such, many researchers have studied its effects on outcomes within the ED. We present novel results regarding the impacts of ED crowding on system performance outside the ED, specifically post-ED care utilization. Methodology: We utilize a dataset assembled from more than four years of microdata from a large U.S. hospital and exhaustive billing data in an integrated health system. We use count models and instrumental variable analyses to answer the proposed research questions. Results: We show that there is an increasing concave relationship between ED physician workload and post-ED care use. When ED workload increases from its 5th percentile to the median, the number of post-discharge care events (i.e., medical services) for patients who are discharged home from the ED increases by 5%. Further, we identify physicians’ test ordering behavior as a mechanism for this effect: when the queue length is high, physicians respond by ordering more tests for less severe patients in the queue. We document that this “extra” testing generates “extra” post-ED care utilization for these patients. Managerial Implications: This paper contributes new insights on how physicians’ and patients’ behavior under ED crowding impacts a previously unstudied system performance measure: post-ED care utilization. Our findings suggest that prior studies estimating the cost of ED crowding provide an underestimate of the true effect, as they do not consider the “extra” post-ED care utilization.