Neutrophil-to-Lymphocyte Ratio as a Prognostic Marker of Disease Severity in Community-Acquired Pneumonia Among Hospitalized Patients From Northeast India

TL;DR

This study shows that a high neutrophil-to-lymphocyte ratio (NLR) predicts severe outcomes in pneumonia patients in Northeast India.

Contribution

The study provides new evidence on NLR's prognostic value for pneumonia in an under-researched Indian population.

Findings

NLR strongly correlates with disease severity (r = 0.72) in CAP patients.

NLR ≥ 9.5 predicts ICU admission, and NLR ≥ 16 is linked to higher mortality.

Middle-aged men and right middle zone pneumonia were most commonly observed.

Abstract

Background: The role of the neutrophil-to-lymphocyte ratio (NLR) as a prognostic marker for community-acquired pneumonia (CAP) has not been extensively studied in India. Therefore, we conducted this study to assess the role of the NLR in determining prognosis and severity among hospitalized CAP patients from Northeast India.

Materials and methods: This prospective observational study was conducted from October 2023 to November 2024 in a tertiary care hospital in southern Assam, Northeast India. A total of 162 adult patients with CAP were recruited for the study via consecutive sampling. Statistical analysis included descriptive statistics, chi-square tests, correlation analysis, and logistic regression to evaluate associations between NLR, severity scores (CURB-65), and patient outcomes.

Results: A strong positive correlation (r = 0.72) was noted between the NLR and CURB-65 score. A level of NLR ≥ 9.5 anticipated the need for intensive care unit (ICU) admission (40.74%, n=66 out of 162), while NLR ≥ 16 was associated with a higher death rate (80%, n=16; out of 20 deaths) compared to NLR <16 (20%, n=4). Most patients (55%) were middle-aged men. Right middle zone pneumonia (22.8%) was the most frequent radiological finding, while 85.18% patients had sterile sputum culture. Both Klebsiella pneumoniae (6.2%) and Streptococcus pneumoniae (6.2%) were the most typical organisms noted in the culture specimen.

Conclusion: An elevated NLR is a strong predictor of disease severity, ICU requirement and mortality amongst Indian CAP patients.

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