277: The Association Between Length of Emergency Department Boarding and Mortality: A Multicenter Study

Abstract

Study Objectives Emergency department (ED) boarding has been associated with several negative patient-oriented outcomes, from dissatisfaction to higher inpatient mortality rates. The current study evaluates the association between length of ED boarding and outcomes at three distinct hospital settings. We hypothesized that prolonged ED boarding of admitted patients would be associated with higher mortality rates and longer hospital length of stay, but that this effect may differ across hospital settings. Methods Study Design-Retrospective cohort study. Setting-one suburban and one urban academic ED, and one urban community ED with a combined annual ED census of 160,000. Subjects-Consecutive patients visiting the suburban ED from 9/05-9/08 and the other two facilities from 1/04-12/06. Measures and Outcomes-An electronic medical record system was used to extract patient demographics, ED disposition (discharge, admit to floor), ED and hospital length of stay (LOS), and inhospital mortality. Boarding was defined as ED LOS >2 hrs after calling in admission. Data Analysis-descriptive statistics were used to evaluate the association between length of ED boarding and hospital LOS, subsequent transfer to an ICU, and mortality controlling for disease/injury severity. Results There were 15546 admissions in the suburban ED, 9536 in the urban academic ED, and 7350 in the urban community ED. In the suburban setting, mortality generally increased with increasing boarding time from 4.9% in patients boarded less than 2 hours to 6.3% in patients boarding 24 or more hours (p < .001). Hospital LOS also showed an increase with boarding time (p < .001). The increases were still apparent after adjustment for co-morbid conditions and other factors. In Research Forum Abstracts contrast, mortality and hospital LOS in the urban settings were not associated with length of boarding. Conclusion The association between length of ED boarding and hospital mortality varies from hospital to hospital. Efforts to mitigate the effect of ED boarding on outcomes should be tailored to local hospital settings.