Work

Validation of FEN-COVID phenotypes in hospitalised COVID-19 patients across the first four waves of the pandemic

Year: 2026

Type: article

Abstract: INTRODUCTION: The FEN-COVID study identified 3 clinical phenotypes (PhA, PhB and PhC) in hospital-admitted patients with COVID-19, which were associated with mortality. The aim of this study is to validate the assignment to phenotypes and their association with mortality in two hospitals in Spain across the first 4 waves of the pandemic, including the impact of corticosteroids and anticoagulant drugs. METHODS: A prospective cohort study of patients admitted for COVID-19 in the first 4 waves in two hospitals was performed. Phenotypes were assigned using the FEN-COVID calculator. The primary outcome was 30-day all-cause mortality. Kaplan-Meier (KM) curves were compared using the log-rank test. Multivariate analysis was performed using Cox regression analysis to assess the association of phenotypes with mortality. RESULTS: 1839 patients were included. Of these, 257 patients were identified as PhA, 1451 as PhB and 130 as PhC; their 30-day mortality was 1.9%, 15.4% and 45.4%, respectively. In multivariate analysis and controlling for wave effect, belonging to phenotype B and phenotype C was associated with progressive increased hazards of death. In addition, appropriate treatment with corticosteroids was significantly associated with lower mortality in PhB, while low-molecular weight heparin use was significantly associated with lower mortality in PhB and PhC. CONCLUSIONS: Our results confirmed that the clinical phenotypes identified in the FEN-COVID study were predictive of mortality across all waves studied. Furthermore, we confirmed the importance of identifying the phenotype to which a patient belongs on admission when considering appropriate treatment with corticosteroids and/or anticoagulants.

Source: Enfermedades infecciosas y microbiologia clinica (English ed )

DOI: 10.1016/j.eimce.2026.503059