External Validation of the 4C (Coronavirus Clinical Characterization Consortium) Mortality Score in a Teaching Hospital in Brazil.

Background The 4C (Coronavirus Clinical Characterization Consortium) Mortality Score has demonstrated good discrimination in COVID-19 but has not been widely validated in Brazil. The 4C Mortality Score is a clinical tool developed during the COVID-19 pandemic to predict in-hospital mortality for patients admitted with COVID-19. It was derived from a large dataset of hospitalized patients in the United Kingdom and provides a simple yet effective way to stratify patients based on their risk of death. Objective This study aimed to determine the accuracy of the 4C Mortality Score in patients admitted with COVID-19 in a university teaching hospital. Methods The study was observational, longitudinal, and retrospective, conducted in a 180-bed university teaching hospital in Rio de Janeiro, Brazil. We included all patients admitted with COVID-19 and followed them until discharge. The 4C Mortality Score was calculated based on age, sex, Charlson index, respiratory rate, peripheral oxygen saturation (room air), Glasgow Coma Scale, serum urea, and C-reactive protein (CRP) level. The primary outcome was mortality. Results We included 208 participants, with a median age of 63 years. Among them, 111 (53%) were male; 52 (25%) had cardiovascular disease, and 83 (39%) had cancer. Mortality was 39.9%. Independent predictors of mortality were age, hemoglobin, CRP, mechanical ventilation, and the need for vasopressors. The 4C Mortality Score's area under the receiver operating characteristic curve (AUC-ROC) was 89.9%. Conclusion The 4C Mortality Score demonstrated excellent discrimination in a teaching hospital population.