High Neutrophil-to-Lymphocyte Ratio Predicts Stroke-Associated Pneumonia in Intracerebral Hemorrhage A Propensity Score Matching Analysis

Abstract Background Inflammatory mechanisms play important roles in intracerebral hemorrhage (ICH) and have been linked to the development of stroke-associated pneumonia (SAP). The neutrophil-to-lymphocyte ratio (NLR) is an inflammatory index that reflects systemic inflammatory responses after stroke. In this study, we aimed to evaluate the predictive value of the NLR for SAP and ICU admission in patients with ICH. Methods Patients with ICH in four hospitals were prospectively enrolled. Data on the NLR were collected at admission, and the correlation between these factors and the clinical pulmonary infection score (CPIS) was assessed through Spearman’s analysis. Outcomes at discharge were collected and assessed by the modified Rankin scale (mRS). Propensity score matching (PSM) analysis was used to compare outcomes between the groups. Results A total of 320 patients were enrolled in this study, among whom 126 (39.4%) developed SAP. A total of 176 patients were enrolled in the PSM cohort, among whom 66 (37.5%) developed SAP. The results of the receiver operating characteristic (ROC) analysis revealed that the NLR had predictive value for SAP in both the original cohort (AUC: 0.748, 95% CI: 0.695–0.801) and PSM cohort (AUC: 0.657, 95% CI: 0.575–0.739). The NLR also predicted ICU admission in both the original cohort (AUC: 0.732, 95% CI: 0.671–0.786) and the PSM cohort (AUC: 0.646, 95% CI: 0.563–0.723). The NLR remained significant after adjusting for other confounders in the multivariable analysis in both the original cohort (adjusted OR = 1.090, 95% CI: 1.029–1.155, P = 0.003) and PSM cohort (adjusted OR = 1.057, 95% CI, 1.004–1.113, P = 0.034). Spearman’s analysis showed that the NLR was correlated with the CPIS in both the original cohort (r = 0.537, 95% CI: 0.395–0.654) and PSM cohort (r = 0.504, 95% CI: 0.292–0.669). ROC curve analysis also showed that the NLR predicted poor outcomes at discharge in both the original cohort (AUC: 0.761, 95% CI: 0.707–0.815) and the PSM cohort (AUC: 0.584, 95% CI: 0.500–0.670). Conclusions A high NLR value at admission predicted SAP in patients with ICH, and the best cutoff value was 6.06. The NLR also contributed to predicting severe SAP and ICU admission. Patients with higher NLR levels had higher in-hospital mortality and poorer outcomes at discharge.