Does Neutrophil-to-lymphocyte Ratio at Admission Predict Severity and Mortality in COVID-19 Patients? A Systematic Review and Meta-analysis

Prattay Guha Sarkar; Pragya Pant; Jagmohan Kumar; Amit Kumar

doi:10.5005/jp-journals-10071-24135

Does Neutrophil-to-lymphocyte Ratio at Admission Predict Severity and Mortality in COVID-19 Patients? A Systematic Review and Meta-analysis

Indian J Crit Care Med. 2022 Mar;26(3):361-375. doi: 10.5005/jp-journals-10071-24135.

Authors

Prattay Guha Sarkar¹, Pragya Pant², Jagmohan Kumar³, Amit Kumar⁴

Affiliations

¹ Department of Cardiology, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India.
² Department of Nephrology, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India.
³ Department of Medicine, Palamu Medical College, Daltonganj, Jharkhand, India.
⁴ Department of Laboratory Medicine, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India.

Abstract

Background: Coronavirus disease-2019 (COVID-2019) pandemic continues to be a significant public health problem. Severe COVID-19 cases have a poor prognosis and extremely high mortality. Prognostic factor evidence can help healthcare providers understand the likely prognosis and identify subgroups likely to develop severe disease with increased mortality risk so that timely treatments can be initiated. This meta-analysis has been performed to evaluate the neutrophil-to-lymphocyte ratio (NLR) at admission as a prognostic factor to predict severe coronavirus disease and mortality.

Materials and methods: A literature search was conducted through April 30, 2021, to retrieve all published studies, including gray literature and preprints, investigating the association between NLR and severity or mortality in COVID-19 patients. Screening of studies and data extraction have been done by two authors independently. The methodological quality of the included studies was assessed by the Quality in Prognosis Studies (QUIPS) tool.

Results: Twenty-four studies involving 4,080 patients reported the prognostic value of NLR for severe COVID-19. The pooled sensitivity (SEN), specificity (SPE), and area under the curve were 0.75 (95% CI 0.69-0.80), 0.74 (95% CI 0.70-0.78), and 0.81 (95% CI 0.77-0.84). Fifteen studies involving 4,071 patients reported the prognostic value of NLR for mortality in COVID-19. The pooled sensitivity (SEN), specificity (SPE), and area under curve were 0.80 (95% CI 0.72-0.86), 0.78 (95% CI 0.69-0.85), and 0.86 (95% CI 0.83-0.89).

Conclusion: The prognostic value of NLR at admission for severity and mortality in patients with COVID-19 is good. Evaluating the NLR at admission can assist treating clinicians to identify early the cases likely to worsen. This would help to conduct early triage, identify potentially high-risk cases, and start optimal monitoring and management, thus reducing the overall mortality of COVID-19.

Trial registry: This meta-analysis was prospectively registered on PROSPERO database (Registration Number: CRD42021247801).

How to cite this article: Sarkar PG, Pant P, Kumar J, Kumar A. Does Neutrophil-to-lymphocyte Ratio at Admission Predict Severity and Mortality in COVID-19 Patients? A Systematic Review and Meta-analysis. Indian J Crit Care Med 2022;26(3):361-375.

Keywords: COVID-19 ARDS; COVID-19 mortality; Neutrophil-to-lymphocyte ratio; Prognosis.