Significance of Neutrophil-lymphocyte Ratio, Neutrophil-platelet Ratio, and Neutrophil-to- lymphocyte and Platelet Ratio in Predicting Outcomes in Dengue Patients on Admission in Wardha, Maharashtra, India: A Retrospective Cohort Study

Introduction: Dengue is an important viral infectious disease, mostly seen in tropical countries during the rainy season, and is emerging as a public health hazard for healthcare facilities. The most common parameters used to assess the severity of dengue are platelet count and haematocrit. However, new haematological parameters have emerged to predict the severity of dengue fever and assist clinicians, especially in resource-limited settings.Aim: To highlight the significance of Neutrophil-Lymphocyte Ratio (NLR), Neutrophil-Platelet Ratio (NPR), and Neutrophil-to-Lymphocyte and Platelet Ratio (NLPR) in predicting outcomes in patients with dengue infection.Materials and Methods: A retrospective observational study was conducted in rural central India in the Department of Medicine at Jawaharlal Nehru Medical College, Wardha, Maharashtra, India. A total of 540 patients infected with the dengue virus between June 2021 and December 2021. Data analysis was conducted from January to April 2022. Neutrophil, platelet, and lymphocyte counts were used to calculate NLR, NPR, and NLPR, and their roles in predicting the final outcome were studied. The final analysis was performed using the Statistical Package for Social Sciences (SPSS) software, version 21.0. The p-value<0.05 than 0.05 was considered statistically significant.Results: The mean age of the patients was 29.85 +/- 13.40 years, ranging from 18 to 85 years, with a median age of 25 years. A total of 331 (61.7%) patients below 30 years of age were significantly higher than patients aged 30 years or older (38.3%) (Z=3.39; p=0.0007). The Area Under Curve (AUC) for NLR (0.852) was higher than that for NLPR (0.828) and NPR (0.708). Therefore, NLR was more effective in predicting adverse outcomes compared to NLPR and NPR. However, the efficacies of NLR and NLPR seemed to be more or less equal.Conclusion: The NLR was a better predictor of outcome or severity in dengue fever when compared to NPR and NLPR. Hence, it can be a cost-effective tool used by physicians working in rural hospitals with limited resources.