Neutrophil-to-Lymphocyte Ratio as Predictor of Severity and Mortality in COVID-19 Patients in Millennium COVID-19 Care Center, Addis Ababa, Ethiopia.

Abstract

Abstract Background: The global COVID-19 pandemic has infected millions of the world's population and resulted in huge stress on the health care system of all countries in the world. Early identification of patients who are at high risk of poor clinical outcomes is a key to success in the management of the disease and saving the lives of patients with coronavirus disease 2019 (COVID-19) in the context of limited medical resources. Neutrophil to Lymphocyte ratio is an easily available and cheap surrogate inflammatory marker, whether baseline NLR could be an independent predictor of in-hospital death and severity in the context of African COVID-19 patients remains to be investigated and standardized threshold level of NLR have not been well demonstrated. Objective: This study aims to evaluate the role of NLR as a valuable predictor of Severity and in-hospital mortality in patients with COVID-19. Methods: A cross-sectional study was conducted on patients with COVID-19 admitted to Millennium COVID 19 care center from August 1 to October 30/2021. The data was collected retrospectively and analysis was made on SPSS 26. Receiver Operating Characteristic curve analysis was used to calculate the area under the curve to assess the predictive capacity of NLR on mortality and severity, and to set the cutoff value. Binary and multivariable logistic regression analysis was performed to identify the association between independent variables and disease outcomes with an adjusted odds ratio (AOR), P-value, and 95%CI for AOR were used for testing significance. Result: The NLR of 9.47 was identified as optimal cut-off value of predicting mortality with a sensitivity of 88.7% and a specificity of 95.4% (area under the curve (AUC): 0.95, 95% CI 0.92- 98; P < 0.0001) and NLR of 5.86 was an effective threshold value in predicting the severity of disease with a sensitivity of 92.2% and specificity of 75% (AUC: 0.858, 95% CI 0.95-90; P < 0.0001). In multivariate logistic regression analysis, after adjusting for confounding factors, NLR more than 9.47 was significantly associated with all‐cause of in‐hospital mortality (AOR= 4.73, 95%CI, 1.19-33.68; P < 0.02), and value more than 5.86 was significantly associated with severity of disease (AOR=12.98, 95%CI 3.85-43.80; P=0.001). Conclusion and recommendation NLR is a simple inflammatory biomarker that is easily detected at admission, patients having NLR≥9.47and ≥5.86 effectively predict in the hospital all-cause of mortality and severity of the disease. It provides an objective input for early decision-making inpatient management and allocation of resources. Keyword: COVID 19, Neutrophil-to-Lymphocyte ratio