The value of the neutrophil-lymphocyte count ratio in the diagnosis of sepsis in patients admitted to the Intensive Care Unit: A retrospective cohort study

Background Early diagnosis and treatment has proven to be of utmost importance in the outcome of sepsis patients. We compared the accuracy of the neutrophil-lymphocyte count ratio (NLCR) to conventional inflammatory markers in patients admitted to the Intensive Care Unit (ICU). Methods We performed a retrospective cohort study consisting of 276 ICU patients with sepsis and 388 ICU patients without sepsis. We compared the NLCR as well as C-reactive protein (CRP) level, procalcitonin (PCT) level, white blood cell (WBC) count, neutrophil count and lymphocyte count on ICU admission between sepsis and non-sepsis ICU patients. To evaluate the sensitivity and specificity, we constructed receiver operating characteristics (ROC) curves. Results Significant differences in NLCR values were observed between sepsis and non-sepsis patients (15.3 [10.8–38.2] (median [interquartile range] vs. 9.3 [6.2–14.5]; P<0.001), as well as for CRP level, PCT level and lymphocyte count. The area under the ROC curve (AUROC) of the NLCR was 0.66 (95%CI = 0.62–0.71). AUROC was significantly higher for CRP and PCT level with AUROC’s of 0.89 (95%CI 0.87–0.92) and 0.88 (95%CI 0.86–0.91) respectively. Conclusions The NLCR is less suitable than conventional inflammatory markers CRP and PCT to detect the presence of sepsis in ICU patients. Trial registration ClinicalTrials.gov NCT01274819 .