Neutrophil-Lymphocyte Count Ratio Better Predict Prognosis than Conventional Markers in Critical Patients? A Multiple-Centered Retrospective Cohort Study

Background: Neutrophil-lymphocyte count ratio (NLCR) has been reported as better indicator of bacteremia than procalcitonin (PCT), and better predictor of mortality than C-reactive protein (CRP) in various medical conditions. However, large controversy remains upon this topic. We compared the efficiency of NLCR with conventional inflammatory markers in predicting the prognosis of critical illness. Methods: We performed a multiple-centered retrospective cohort study consisting of 536 ICU patients with outcomes of survival, 28- and 7-day mortality. NLCR was compared with conventional inflammatory markers such as PCT, C-reactive protein (CRP), serum lactate (LAC), white blood cell, neutrophil and severity score APACHE II (Acute Physiology and Chronic Health Evaluation II) to evaluate the predictive value on outcomes of critical illness. Then receiver operating characteristics (ROC) curves were constructed to assess and compare each marker’s sensitivity and specificity respectively. Results: NLCR values were not differential among survival and mortality groups. Meanwhile remarkable differences were observed upon APACHE II score, CRP, PCT and LAC levels among survival and death groups. ROC analysis revealed that NLCR was not competent to predict prognosis of critical illness. The AUROCs of conventional markers such as CRP, PCT, LAC and APACHE II score were more significant in predicting 28- and 7-day mortality. Conclusions: NLCR is not competent and less reliable than conventional markers CRP, PCT, LAC and APACHE II score in assessing severity and in predicting outcomes of critical illness.