The COVID-19 pandemic has been challenging for healthcare systems in the United States and globally. Understanding how the COVID-19 pandemic has impacted emergency departments (EDs) and patient outcomes in a large integrated healthcare system may help prepare for future pandemics. Our primary objective was to evaluate if there were changes to ED boarding and in-hospital mortality before and during the COVID-19 pandemic.

This was a retrospective cohort study of all patients ages 18 and over who presented to one of 17 EDs (11 hospital-based; 6 freestanding) within our healthcare system. The study timeframe was March 1, 2019- February 29, 2020 (pre-pandemic) vs. March 1, 2020-August 31, 2021 (during the pandemic). Categorical variables are described using frequencies and percentages, and p-values were obtained from Pearson chi-squared or Fisher's exact tests where appropriate. In addition, multiple regression analysis was used to compare ED boarding and in-hospital mortality pre-pandemic vs. during the pandemic.

A total of 1,374,790 patient encounters were included in this study. In-hospital mortality increased by 16% during the COVID-19 Pandemic AOR 1.16(1.09–1.23, p < 0.0001). Boarding increased by 22% during the COVID-19 pandemic AOR 1.22(1.20–1.23), p < 0.0001). More patients were admitted during the COVID-19 pandemic than prior to the pandemic (26.02% v 24.97%, p < 0.0001). Initial acuity level for patients presenting to the ED increased for both high acuity (13.95% v 13.18%, p < 0.0001) and moderate acuity (60.98% v 59.95%, p < 0.0001) during the COVID-19 pandemic.

The COVID-19 pandemic led to increased ED boarding and in-hospital mortality.