Emergency department boarding and adverse hospitalization outcomes among patients admitted to a general medical service Kito Lord, MD, MBA a , Vivek Parwani, MD a , Andrew Ulrich, MD a , Emily B. Finn, MPH b , Craig Rothenberg, MPH a , Beth Emerson, MD b,c , Alana Rosenberg, MPH b , Arjun K. Venkatesh, MD, MBA, MHS a,d, ⁎ a Department of Emergency Medicine, Yale University School of Medicine, New Haven, CT, United States b Center for Healthcare Innovation, Redesign and Learning, Yale University, New Haven, CT, United States c Section of Pediatric Emergency Medicine, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, United States d Center for Outcomes Research and Evaluation, Yale University School of Medicine, New Haven, CT, United States abstract article info Article history: Received 19 February 2018 Accepted 19 March 2018 Available online xxxx Objective: Overcrowding in the emergency department (ED) has been associated with patient harm, yet little is known about the association between ED boarding and adverse hospitalization outcomes. We sought to examine the association between ED boarding and three common adverse hospitalization outcomes: rapid response team activation (RRT), escalation in care, and mortality. Method: We conducted an observational analysis of consecutive patient encounters admitted from the ED to the general medical service between February 2013 and June 2015. This study was conducted in an urban, academic hospital with an annual adult ED census over 90,000. We defined boarding as patients with greater than 4 h from ED bed order to ED departure to hospital ward. The primary outcome was a composite of adverse outcomes in the first 24 h of admission, including RRT activation, care escalation to intensive care, or in-hospital mortality. Results: A total of 31,426 patient encounters were included of which 3978 (12.7%) boarded in the ED for 4 h or more. Adverse outcomes occurred in 1.92% of all encounters. Comparing boarded vs. non-boarded patients, 41 (1.03%) vs. 244 (0.90%) patients experienced a RRT activation, 53 (1.33%) vs. 387 (1.42%) experienced a care es- calation, and 1 (0.03%) vs.12 (0.04%) experienced unanticipated in-hospital death, within 24 h of ED admission. In unadjusted analysis, there was no difference in the composite outcome between boarding and non-boarding patients (1.91% vs. 1.91%, p = 0.994). Regression analysis adjusted for patient demographics, acuity, and comor- bidities also showed no association between boarding and the primary outcome. A sensitivity analysis showed an association between ED boarding and the composite outcome inclusive of the entire inpatient hospital stay (5.8% vs. 4.7%, p = 0.003). Conclusion: Within the first 24 h of hospital admission to a general medicine service, adverse hospitalization out- comes are rare and not associated with ED boarding. © 2018 Elsevier Inc. All rights reserved. Keywords: Emergency department Boarding Overcrowding 1. Introduction Emergency Department (ED) overcrowding has steadily worsened over the past two decades as the ED increasingly becomes the de facto site for acute, unscheduled care and the primary entry point for patients requiring hospitalizations [1]. ED overcrowding has been associated with poor clinical outcomes, including delays in pain management and treatment for acute myocardial infarction; medication errors; and in-hospital mortality [2,3]. An important but poorly studied factor in ED overcrowding is boarding, the time interval between an inpatient bed order and when a patient leaves the ED. Patients may be uniquely vulnerable to harm during this period as home medications are often delayed and account- ability for care may be ambiguous [4]. Several studies have suggested an association between ED boarding of ICU patients and mortality [5-7], but less is known about general medical admissions and adverse out- comes that may suggest harm of lesser severity than mortality [8,9]. With the attention given to short-term adverse hospitalization events by quality improvement staff, further elucidating the relationship be- tween ED boarding and hospitalization outcomes is essential to both ED and hospital leaders. American Journal of Emergency Medicine xxx (2018) xxx–xxx ⁎ Corresponding author at: 464 Congress Suite 260, New Haven, CT 06511, United States. E-mail addresses: klord1@uthsc.edu (K. Lord), vivek.parwani@yale.edu (V. Parwani), andrew.ulrich@yale.edu (A. Ulrich), e.finn@yale.edu (E.B. Finn), craig.rothenberg@yale.edu (C. Rothenberg), beth.emerson@yale.edu (B. Emerson), alana.rosenberg@yale.edu (A. Rosenberg), arjun.venkatesh@yale.edu (A.K. Venkatesh). YAJEM-57394; No of Pages 3 https://doi.org/10.1016/j.ajem.2018.03.043 0735-6757/© 2018 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect American Journal of Emergency Medicine journal homepage: www.elsevier.com/locate/ajem Please cite this article as: Lord K, et al, Emergency department boarding and adverse hospitalization outcomes among patients admitted to a general medical service, American Journal of Emergency Medicine (2018), https://doi.org/10.1016/j.ajem.2018.03.043