Predictive accuracy of neutrophil-to-lymphocyte ratio on severity and outcomes in COVID-19 patients: A retrospective study

Background/Aims: Neutrophil-to-lymphocyte ratio (NLR) is a proven marker in coronavirus disease 2019 (COVID-19) severity and mortality. However, the utility of a sequential NLR 2 (on day 5) in comparison to baseline NLR in predicting clinical outcomes and severity remains largely unexplored. Methods: This was a hospital-based retrospective observational study. Results: Higher mortality (19.9% vs. 48%) and a more severe disease (14.8% vs. 21%) were observed with elevated NLR 1 and NLR 2, respectively. NLR 2 at a cutoff of 9.88 was a better predictor of mortality, when compared to NLR 1 at 5.67, and NLR 2 has a strong correlation with mortality rates in COVID-19. Conclusion: Our study demonstrated that NLR 1 and NLR 2 were more reliable predictors of mortality than disease severity; in comparison, NLR 2 is a more accurate predictor of mortality than NLR 1. The study unravels the potential role of a sequential NLR 2, to have a better correlation in predicting the clinical severity and outcomes. The potential role of NLR 2 in assessing the interim progression of the disease and thereby initiating specific interventions at critical junctures to influence the outcome is unveiled and merits exploration in detail by larger studies.