Diagnostic value of neutrophil to lymphocyte ratio for assessing the disease severity in covid-19 patients

INTRODUCTION: Deterioration of the clinical condition in corona virus disease 2019 (Covid-19) patients can be rapid and unpredictable. A sensitive biomarker is required to assess the disease severity to anticipate these condition. Neutrophil to lymphocyte ratio (NLR) is easily calculated from a complete blood count parameters, so it can be used as a biomarker to assess disease severity in Covid-19 patients.
METHODS: Patients characteristic and NLR were obtained from patients confirmed by Covid-19 at Udayana University Hospital, Bali, Indonesia from April to September 2020. The Mann Whitney U test is used to determine the difference of NLR in severe and non-severe cases of Covid-19. The receiver operating characteristic curve (ROC) is used to determine the optimal cut-off value, sensitivity, specificity, and area under curve (AUC) of the NLR in assessing disease severity in Covid-19 patients. Binary logistic regression analysis was performed to determine the effect of age, comorbidities and other significant variables that have a significant effect on disease severity.
RESULTS: A total of 411 patients were included in this study. We found a significant difference of NLR between severe and non-severe cases of Covid-19 (p < 0.001). We found an optimal NLR cut-off value of 3.0, with 81.4% sensitivity, 81.2% specificity, and area under curve of 0.886 (95% confidence interval (CI) 0.848 – 0.923; p < 0.001).
DISCUSSION AND CONCLUSION: Neutrophil to lymphocyte ratio is a biomarker that has a high diagnostic value for assessing the disease severity in Covid-19 patients