Mark H. Ebell, MD, MS; Roya Hamadani, MPH; Autumn Kieber-Emmons, MD, MPH
Corresponding Author: Mark H. Ebell, MD, MS; Department of Epidemiology and Biostatistics - College of Public Health - University of Georgia.
Contact Email: ebell@uga.edu
Section: Original Research
Ahead of Print Version: www.jabfm.org/content/early/2022/09/15/jabfm.2022.AP.220056
Final Publication Date: TBD
BACKGROUND: Outpatient physicians need guidance to support decisions regarding hospitalization of COVID-19 patients and how closely to follow outpatients.
OBJECTIVE: To develop and validate simple risk scores to predict hospitalization for outpatients with COVID-19 that do not require laboratory testing or imaging, including during the Omicron wave.
DESIGN: Derivation and validation of clinical prediction rules.
SETTING: Primary and urgent care clinics in a Pennsylvania health system.
PATIENTS: Patients 12 years and older presenting who had a positive polymerase chain reaction test for SARS-CoV-2
MEASUREMENTS: Classification accuracy (percent in each risk group hospitalized) and area under the receiver operating characteristic curve (AUC).
RESULTS: Overall, 4.0% of 5843 outpatients in the early derivation cohort (before 3/1/21), 4.2% of 3806 outpatients in the late validation cohort (3/1/21 to 9/30/21), and 1.2% in an Omicron cohort were hospitalized. The base risk score included age, dyspnea, and any comorbidity. Other scores added fever, respiratory rate and/or oxygen saturation. All had very good overall accuracy (AUC 0.85-0.87) and classified about half of patients into a low-risk group with < 1% hospitalization risk. Hospitalization rates in the Omicron cohort were 0.22%, 1.3% and 8.7% for the base score. Two externally derived risk scores identified more low risk patients, but with a higher overall risk of hospitalization than our novel risk scores.
LIMITATIONS: Data were obtained retrospectively from an electronic health record.
CONCLUSIONS: A simple risk score suitable for outpatient and telehealth settings can classify over half of COVID-19 outpatients into a very low risk group with a 0.22% hospitalization risk in the Omicron cohort. The Lehigh Outpatient COVID Hospitalization (LOCH) risk score is available online as a free app: https://ebell-projects.shinyapps.io/LehighRiskScore/.