The prognostic and risk-stratified value of neutrophil–lymphocyte count ratio in Chinese patients with community-acquired pneumonia

Abstract

Community-acquired pneumonia is a common disease associated with high mortality. This retrospective study examined whether the neutrophil–lymphocyte count ratio (NLR), already widely used as an index of inflammation, can be used to predict in-hospital mortality of adults with community-acquired pneumonia. Clinical characteristics, CURB-65 and pneumonia severity index score of pneumonia severity, NLR, serum levels of C-reactive protein and procalcitonin, and in-hospital mortality were analyzed for 318 consecutive adults with community-acquired pneumonia admitted to West China Hospital between July 2012 and December 2013. The ability of NLR and other parameters to predict in-hospital mortality was assessed using receiver operating characteristic (ROC) curves. Results showed that NLR increased with increasing CURB-65 ( P < 0.05) and pneumonia severity index ( P < 0.05), and NLR correlated positively with serum levels of C-reactive protein (r = 0.239, P < 0.05) and procalcitonin (r = 0.211, P < 0.05). The median value of NLR was significantly higher among patients who died in hospital (11.96) than among those who were alive at the end of hospitalization (4.19, P < 0.05). Based on a cut-off NLR of 7.12, this index predicted in-hospital mortality with a sensitivity of 82.61% and specificity of 72.20% (area under ROC curve, 0.799). Predictive power was greater for the combination of NLR and serum levels of C-reactive protein and procalcitonin. These results suggest that NLR may be useful for predicting prognosis in Chinese adults with community-acquired pneumonia, and it may work better in combination with traditional markers.