Predictive ability of complete blood count, mean platelet ratio, mean platelet volume, and neutrophil/lymphocyte ratio for severe pneumonia among RT-PCR or radiologically proven COVID-19 patients.

Background: Immuno-inflammatory markers related to white blood cells, and platelets are shown to be associated with COVID-19 infection, and considered to be independent markers for clinical outcomes and mortality. The present study aimed to study the predictive value of these hematologic parameters in progression of COVID-19 to severe pneumonia. Methods: This was an analytical cross-sectional study conducted among RT-PCR or radiologically proven COVID-19 patients in a tertiary care hospital in Rajasthan. Semi-structured questionnaire was used to collect the epidemiological information of the patients with COVID-19. Complete blood count and other laboratory parameters were also studied among the patients. Results: Mean age of participants in the study was 52 years, with about 70% being males. Cough and breathlessness were the most common symptoms among the patients. It was found that the parameters related to white blood cells were significantly different between patients with COVID-19 infection and severe pneumonia (except absolute monocyte count). NLR was significantly higher among those with severe pneumonia. In the univariate analysis, age (OR - 1.02), NLR (OR - 1.16), and albumin (OR - 0.45) were found to be significant predictors of progression to severe pneumonia. In the final model, adjusted for confounders, only NLR and albumin levels significantly predicted progression to severe pneumonia among COVID-19 patients. Conclusion: The study consolidates the predictive ability of NLR for severe pneumonia. It is an important finding, as health facilities with limited access to laboratory investigations can rely on simple markers in routine practice to predict the progression of COVID-19 infection to severe pneumonia.