# Warning indicators of COVID-19 severity: a retrospective observational study integrating modern biomarkers and traditional tongue features

## TL;DR

This study combines modern biomarkers and traditional Chinese medicine tongue features to predict severe COVID-19 early.

## Contribution

It introduces a novel integration of TCM tongue features with clinical biomarkers for predicting disease severity.

## Key findings

- Age, fever, elevated procalcitonin, thick tongue fur, and fat tongue shape were significant predictors of severity.
- A combined model using these factors showed strong predictive performance (Nagelkerke R² = 0.741).

## Abstract

This study aims to identify early warning indicators of COVID-19 severity by integrating modern medical biomarkers with traditional Chinese medicine (TCM) tongue features.

A retrospective observational study was conducted on 409 hospitalized COVID-19 patients from two centers in China. Patients were stratified into severe (n = 50) and non-severe (n = 359) groups based on the 10th edition of China’s diagnostic guidelines. Data included demographics, clinical symptoms, tongue characteristics, and laboratory parameters. Univariate analyses (chi-square/Fisher’s exact tests) and stepwise logistic regression were performed to identify key predictors.

Age (p < 0.001), fever (p < 0.001), elevated procalcitonin (PCT, p < 0.001), thick tongue fur (p = 0.003), and fat tongue shape (p = 0.002) were significant predictors of severity. The combined model integrating these factors demonstrated superior predictive performance (Nagelkerke R2 = 0.741).

Integrating TCM tongue features (thick fur and fat shape) with clinical biomarkers (age, fever, and PCT) enhances early identification of severe COVID-19, particularly in resource-limited settings.