Value of Combining of the NLR and the Fibrinogen Level for Predicting Stroke-Associated Pneumonia

Neuropsychiatr Dis Treat. 2021 May 28:17:1697-1705. doi: 10.2147/NDT.S311036. eCollection 2021.

Abstract

Purpose: To evaluate the value of the NLR (neutrophil-to-lymphocyte ratio) and the fibrinogen level in predicting stroke-associated pneumonia (SAP) in acute ischemic stroke (AIS) patients.

Patients and methods: In total, we enrolled 734 medical-ward patients with AIS in this retrospective study. Patients were divided into SAP (n=52) and non-SAP (n=682) groups according to the diagnostic criteria of SAP. Binary logistic regression analysis was used to analyze the relationship between the NLR, serum fibrinogen concentration and SAP. Receiver operating characteristic (ROC) curves were generated to identify the optimal cutoff points and assess the diagnostic value of the NLR, serum fibrinogen and the combination of NLR and fibrinogen in predicting SAP.

Results: SAP occurred in 52 (7.08%) patients among the enrolled AIS patients. Binary logistic regression analysis showed that the NLR (odds ratio [OR]: 2.802, 95% confidence interval [CI]: 1.302-6.032, P=0.008) and serum fibrinogen concentration (OR: 7.850, 95% CI: 3.636-16.949, P=0.000) were independently associated with a higher risk of SAP incidence after adjusting for age, sex, ASPECT score, atrial fibrillation, nasogastric tube feeding, LDL-C and TC, temperature at admission and mechanical ventilation. The optimal cutoff points of the NLR and serum fibrinogen to distinguish SAP among AIS patients were 3.603 (AUC, 0.690; NPV, 95.78; PPV, 19.01) and 4.595 (AUC, 0.727; NPV, 95.60; PPV, 24.49), respectively. When the combination of NLR and fibrinogen was used to predict SAP, the optimal cutoff points were >2.436 for NLR and >3.24 for fibrinogen (AUC, 0.758; NPV, 98.50; PPV, 11.80).

Conclusion: The NLR and serum fibrinogen might have greater negative diagnostic value in predicting SAP among AIS patients. Combining the NLR and serum fibrinogen showed an increased AUC for predicting SAP among AIS patients.

Keywords: fibrinogen; neutrophil-to-lymphocyte ratio; receiver operating characteristic curve; stroke-associated pneumonia.