Baseline predictors for 28-day COVID-19 severity and mortality among hospitalized patients: results from the IMPACC

Jintong Hou1, Benjamin Haslund-Gourley1, Joann Diray-Arce2

  • 1Department of Microbiology and Immunology/Department of Medicine/Department of Epidemiology & Biostatistics, Drexel University, Philadelphia, PA, United States.

Frontiers in Medicine
|July 21, 2025
PubMed

Insights

The SpO2/FiO2 ratio is the key predictor of COVID-19 severity and mortality. Machine learning models identified clinical and laboratory biomarkers to improve these predictions, outperforming existing scores.

Area of Science:

  • Infectious Diseases
  • Biomarkers
  • Machine Learning

Background:

  • The COVID-19 pandemic overwhelmed healthcare systems globally.
  • Predictive models for COVID-19 severity and mortality are crucial for resource allocation and patient management.

Purpose of the Study:

  • To identify baseline clinical and laboratory biomarkers for predicting COVID-19 severity and mortality.
  • To develop and validate machine learning models for these predictions.

Main Methods:

  • Analysis of data from 1102 hospitalized COVID-19 patients.
  • Utilized lasso and forward selection for predictor identification.
  • Developed and validated predictive models using balanced training and testing data.

Main Results:

  • The SpO2/FiO2 ratio was the strongest predictor of severity (AUC: 0.874) and mortality (AUC: 0.83).
  • Adding biomarkers like age, BMI, FGF23, IL-6, LTA, TNFRSF11B, and ribitol improved prediction accuracy.
  • Developed models outperformed the Sequential Organ Failure Assessment (SOFA) score in certain patient groups.

Conclusions:

  • Machine learning models effectively identify key predictors of COVID-19 outcomes.
  • The SpO2/FiO2 ratio is a critical, easily accessible biomarker for COVID-19 prognosis.
  • Identified biomarkers offer potential for refining risk stratification in hospitalized COVID-19 patients.
Abstract