DR P. TARUN VARMA,DR RAHUL RAJ,DR A. KHALILUR RAHMAN
DOI: https://doi.org/Background: Sepsis remains a major global health concern with high mortality rates, despite advances in critical care. Procalcitonin is widely used as a biomarker but suffers from variable reliability due to elevations in non-infectious conditions and inconsistent cutoff thresholds. The neutrophil-to-monocyte ratio (NMR), derived from complete blood counts, has emerged as a potential low-cost, rapid diagnostic marker.
Objectives: To compare the diagnostic accuracy of NMR and Procalcitonin in predicting sepsis, and to determine an optimal cutoff value for NMR using Receiver Operating Characteristic (ROC) curve analysis.
Methods: This cross-sectional observational study was conducted in the adult intensive care unit of a tertiary care center. A total of 300 patients with suspected sepsis were enrolled, applying qSOFA ≥2 as the reference standard. Complete blood counts and serum Procalcitonin were measured at admission. NMR was calculated as the ratio of absolute neutrophils to monocytes. ROC curve analysis determined the optimal NMR cutoff for sepsis prediction. Diagnostic accuracy parameters, including sensitivity and specificity, were calculated for both biomarkers.
Results: At an ROC-derived cutoff of 18.6, NMR demonstrated a sensitivity of 92.4% and specificity of 68.8%. In comparison, Procalcitonin (cutoff 2 ng/mL) showed lower sensitivity (80.6%) and specificity (59.1%). NMR thus outperformed Procalcitonin in diagnostic performance, with an area under the curve (AUC) indicating good discriminatory power.
Conclusion: NMR is a superior biomarker to Procalcitonin for diagnosing sepsis, offering higher sensitivity and specificity. Its low cost, rapid availability, and reliance on routine blood counts make it especially valuable in resource-limited settings. Larger multicenter studies are needed to validate the generalizability of the cutoff value.
