# A Simple Risk Formula for the Prediction of COVID-19 Hospital Mortality

## TL;DR

This study identifies age and disease severity as key predictors of hospital mortality in non-vaccinated COVID-19 patients.

## Contribution

A simple risk formula using age and oxygenation status is proposed for predicting hospital mortality in non-vaccinated patients.

## Key findings

- Age and disease state are the most significant predictors of hospital mortality.
- An increase in age by 10 years raises mortality risk by 2.5 times.
- A unit increase in oxygenation status raises mortality risk by 20 times.

## Abstract

SARS-CoV-2 respiratory infection is associated with significant morbidity and mortality in hospitalized patients. We aimed to assess the risk factors for hospital mortality in non-vaccinated patients during the 2021 spring wave in the Czech Republic. A total of 991 patients hospitalized between January 2021 and March 2021 with a PCR-confirmed SARS-CoV-2 acute respiratory infection in two university hospitals and five rural hospitals were included in this analysis. After excluding patients with unknown outcomes, 790 patients entered the final analyses. Out of 790 patients included in the analysis, 282/790 (35.7%) patients died in the hospital; 162/790 (20.5) were male and 120/790 (15.2%) were female. There were 141/790 (18%) patients with mild, 461/790 (58.3%) with moderate, and 187/790 (23.7%) with severe courses of the disease based mainly on the oxygenation status. The best-performing multivariate regression model contains only two predictors—age and the patient’s state; both predictors were rendered significant (p < 0.0001). Both age and disease state are very significant predictors of hospital mortality. An increase in age by 10 years raises the risk of hospital mortality by a factor of 2.5, and a unit increase in the oxygenation status raises the risk of hospital mortality by a factor of 20.