Age Dependence of Prognostic Significance of Complete Blood Count Parameters on Mortality from COVID-19

Abstract

The aim of this study is to determine the age dependence of prognostic significance of complete blood count parameters at the time of admission on mortality from the SARS-CoV-2 infection. This is a single-centre retrospective analytic case-control study covering all 2132 patients with COVID-19 treated in the period 2020–2021 in the hospital. Subject of our study is to compare the diagnostic ability of parameters of the complete blood count (CBC) to predict mortality in different age groups using receiver operating characteristics (ROC) and the corresponding area under the curve (AUC) analyses. Out of the red blood cells related parameters, a sufficient accuracy demonstrates only the red blood cell distribution width (RDW-CV), with a gradual decrease of the area under the curve with ageing – from 0.796 in the age groups under 40 and up to 0.601 in the age group of 80 years and above. From the parameters characterizing platelets, the platelet count (PLT), mean platelet volume (MPV) and platelet distribution width (PDW) exhibit a sufficient accuracy only in the age group under 50 years. White blood cells related parameters – white blood count (WBC), granulocytes, granulocytes/lymphocytes ratio (G/L) – demonstrate the best prognostic significance with good accuracy for the age under 50 years – AUC above 0.7, which is retained the same only for granulocytes/lymphocytes ratio in the age group under 70 years. With ageing, we again observe a decline of the accuracy to sufficient in the age groups past 70 years. The results from our study give us grounds to accept that the prognostic value of complete blood count parameters for the prediction of the mortality from COVID-19 is different in various age groups, and decreases with ageing. In patients above 70 years, a limited prognostic value for unfavourable course of the disease have only the RDW-CV and G/L.