Vicka V, Januskeviciute E, Miskinyte S, et al. - Due to continuation of the COVID-19 (coronavirus disease 2019) pandemic, increase in the number of patients admitted to the intensive care unit (ICU) is still obvious, therefore, experts investigated the most accurate conventional ICU mortality risk score for predicting mortality in COVID-19 cases as well as they ascertained how these conventional scores can be employed together with the 4C Mortality Score.

• In this retrospective study, 249 critically ill COVID-19 patients who were treated in tertiary reference COVID-19 hospitals during the year 2020 were included (63.1% were male, average age was 61.32 ± 13.3 years).

• Receiver operating characteristic area under the curve analysis revealed that the Acute Physiology and Chronic Health Evaluation (APACHE) II was the most accurate scale, with an AUC value of 0.772 (95% CI 0.714–0.830; p < 0.001).

• The univariate regression analysis revealed all of the ICU risk scores and 4C Mortality Score as significant mortality predictors.

• An increase in mortality risk by 1.155 and by 1.191 was noted for each point increase in the APACHE II (OR 1.155) and each point increase in the 4C Mortality Score (OR 1.191), respectively, showing the best overall calibration of the model.

• Overall, APACHE II showed the best discrimination of mortality in ICU patients, and both the APACHE II and 4C Mortality Score not only independently predicted death risk but can also be employed concomitantly.