Early Identification of Severe COVID-19 in Hospitalised Patients: A Large, French Multicentre Case Series

Abstract

Background: Early identification of patients at risk for severe coronavirus disease 2019 (COVID-19) is a major issue to help clinicians optimise patient-flow management and allocation of healthcare resources. Methods: This retrospective, observational, multicentre study included all consecutive patients admitted to hospital with COVID-19 across 24 centres in France between February 26 and April 20, 2020. Comprehensive data, including clinical, biological, and imaging variables, were recorded at admission. The primary outcome was a composite of transfer to intensive care unit (ICU) or in-hospital death without transfer to ICU. Findings: Among 2878 patients (57·9% men, 67±17 years), the primary outcome occurred in 838 (29·3%) patients: 19·1% were transferred to ICU and 10·0% died in-hospital without transfer to ICU. Based on the derivation cohort (n=2105), 12 variables were independently associated with the primary outcome in the final model: demographics (age, sex), triage vitals (body temperature, Glasgow coma scale, dyspnoea, respiratory frequency, fraction of inspired oxygen), biological (platelets, C-reactive protein, aspartate aminotransferase, glomerular filtration rate), and imaging (degree of scanographic lesions) data. A risk-stratification score was developed that displayed accurate calibration and discrimination, with C-statistics of 0·80 (95% confidence interval 0·78 to 0·82) in the derivation cohort and 0·79 (95% confidence interval 0·75 to 0·83) in validation cohort. Interpretation: Using data from a multicentre series of patients with COVID-19, we identified independent predictors of severe COVID-19 in hospitalised patients, including clinical, biological, and imaging variables at admission. An accurate integrative risk score was developed and externally validated to optimise early triage of patients. Trial Registration: NCT04344327 Funding Statement: None. Declaration of Interests: None. Ethics Approval Statement: The CCF study was declared to and authorised by the French data protection committee (Commission Nationale Informatique et Liberte, CNIL, authorisation n°2207326v0), and was conducted in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.