The Comorbidities, Radiographic Findings, Age, and Lymphopenia (CORAL) Tool: A Diagnostic Ally for Emergency Physicians Created for the COVID-19 Crisis and Beyond

Background: This study aimed to develop a novel clinical approach to predict intensive care unit (ICU) admission and mortality among coronavirus disease 2019 (COVID-19) patients in the emergency department (ED). Methods: A retrospective cohort study was conducted including adults ≥ 18 years diagnosed with COVID-19 in the emergency department and admitted to the ICU between March and July 2020 in an academic hospital. The outcome variables were mortality and ICU admission. Additional variables that were collected included sex, age, comorbidities, symptom phenotype, and laboratory (lymphopenia) and imaging findings. A logistic regression model was used to construct and validate the risk models. Results: A total of 808 patients were included in the study; 61.9% were men. The mean age was 57.8 ± 15.9 years, and high blood pressure (HBP) was the most prevalent comorbidity (31.8%). Seventy-six (9.4%) patients were admitted to the ICU. Age ≥ 60 years, chronic obstructive pulmonary disease (COPD), lymphopenia, and imaging findings correlated with mortality. Age ≥ 60 years, lymphopenia (<1,000 cells per microliter), and hypothyroidism correlated with ICU admission. These variables were incorporated into a scoring system (Comorbidities, Radiographic findings, Age, and Lymphopenia (CORAL) tool) to predict mortality and ICU admission. Conclusions: Our Comorbidities, Radiographic findings, Age, and Lymphopenia (CORAL) tool is a practical tool for different clinical settings independent of access to advanced medical resources or technologies. CORAL is suitable for emergency physicians in low- and middle-income countries.