Association of the NLR, BNP, PCT, CRP, and D-D with the Severity of Community-Acquired Pneumonia in Older Adults

This study aimed to investigate the value of the neutrophil-to-lymphocyte ratio (NLR), B-type natriuretic peptide (BNP), and D-dimer (D-D) in predicting pneumonia severity in older adults with community-acquired pneumonia (CAP).The retrospective study included older adults with CAP at the General Hospital of Northern Theater Command from January 2017 to December 2019. Patient demographic information and clinical characteristics were collected. Logistic multivariable analysis was used to analyze the factors associated with CAP severity. Receiver operating curve (ROC) analysis was used to evaluate the value of each biomarker in severity prediction.A total of 158 patients were included: 85 with mild-moderate CAP and 73 with severe CAP. The multivariable logistic analysis showed that CRP (OR = 1.011; 95% CI: 1.011 - 1.022; p = 0.039), BNP (OR = 1.003; 95% CI: 1.001 - 1.004; p = 0.001), D-D (OR = 1.289; 95% CI: 1.031 - 1.611; p = 0.026), and NLR (OR = 1.111; 95% CI: 1.011 - 1.222; p = 0.030) were independent factors associated with pneumonia severity. ROC analysis demonstrated the value of each biomarker in pneumonia severity prediction: CRP (AUC = 0.791, 95% CI: 0.720 - 0.861), BNP (AUC = 0.803, 95% CI: 0.649 - 0.806), D-D (AUC = 0.727, 95% CI: 0.734 - 0.872), and NLR (AUC = 0.817, 95% CI: 0.751 - 0.883). The positive and negative predictive values were 0.68 and 0.81 for CRP, 0.79 and 0.75 for BNP, 0.62 and 0.80 for D-D, and 0.80 and 0.76 for NLR.CRP, BNP, D-D, and NLR might be helpful independent factors in predicting pneumonia severity in older adults with CAP.