46 Clinical Characteristics of COVID-19 Patients in the Emergency Department Predict Hospitalization and Critical Illness: A Retrospective Cohort Study

Casey, S. D.; Cotton, D. M.; Liu, L.; Vinson, D. R.; Ballard, D. W.; Shan, J.; Rauchwerger, A. S.; Mark, D. G.; Reed, M. E.

Study Objective: COVID-19 is commonly seen in the emergency department (ED). However, the association between key clinical variables and a patient’s downstream clinical course is incompletely understood. We sought to fill this knowledge gap in order to inform emergency management of the COVID-19 patient. Methods: We performed a retrospective cohort study of adults presenting to 21 U.S. community EDs with symptomatic COVID-19 from 2/21/2020 - 4/5/2020 with an in-system SARS-CoV-2 positive laboratory test 21 days before or after the index visit. Demographic, clinical, radiographic and laboratory variables were collected from electronic health records using a combination of manual chart review and electronic data extraction. We used multivariate logistic regression to examine the association between patient characteristics and two primary outcomes: (1) hospitalization from the index visit;and (2) critical illness, defined as either death or a requirement for respiratory support of high flow nasal cannula, non-rebreather mask, non-invasive ventilation or mechanical ventilation within 21 days. Results: Among 801 study-eligible patients, 28% were ≥65 years of age, 47% were female and 24% were non-Hispanic white. 393 patients (49%) were hospitalized and 161 (20%) had critical illness. Adjusted statistically significant predictors (p<0.05) of initial hospitalization included abnormal pulmonary auscultation, elevated blood urea nitrogen (BUN), measured fever, and abnormal respiratory vital signs (respiratory rate, oxygen saturation). Independent predictors (p<0.05) of critical illness included a history of hypertension, abnormal chest x-ray, elevated neutrophil-to-lymphocyte ratio, elevated BUN, measured fever, and abnormal respiratory vital signs (Table). Conclusion: In this large, diverse study of ED patients with COVID-19 in a pre-vaccine and pre-variant era, we identified clinical variables that were independent predictors of hospitalization and critical illness. Awareness of these key prognostic variables may assist emergency physicians with clinical decision-making. [Formula presented]