European Journal of Cardiovascular Medicine

Background and Objectives: Community-acquired pneumonia (CAP) is a prevalent infectious disease with significant implications for the elderly's health worldwide. This study explores the potential of the Neutrophil Lymphocyte Ratio (NLR) as a biomarker for CAP. Methods: This diagnostic comparative study involved patients aged 18 and above with community-acquired pneumonia under care at a tertiary care hospital in India. Detailed history, clinical assessments, and lab investigations were conducted after obtaining informed consent. NLR, CURB-65 score, and PSI score were computed and statistically analyzed. Result: The study included 246 patients (mean age: 56.8 ± 15.9 years; 60.3% male, 39.7% female). Comparing mild, moderate, and severe risk groups showed significantly higher mean NLR in the severe group. Pearson's correlation revealed positive links between NLR and CURB-65 score, and PSI score. ROC analysis resulted in AUCs of 0.902 (NLR), 0.922 (CURB-65), and 0.931 (PSI), all significant (p < 0.05). Conclusion: Neutrophil Lymphocyte Ratio emerges as a significant biomarker for community-acquired pneumonia. NLR also correlates positively with CURB-65 and PSI scores, offering a simple and effective tool for outcome assessment in CAP patients.