The association between the neutrophil-tolymphocyte ratio and mortality in critical illness: an observational cohort study
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Type
Journal Article
Abstract
Introduction: The neutrophil-to-lymphocyte ratio (NLR) is a biological marker that has been shown to be associated
with outcomes in patients with a number of different malignancies. The objective of this study was to assess the
relationship between NLR and mortality in a population of adult critically ill patients.
Methods: We performed an observational cohort study of unselected intensive care unit (ICU) patients based on
records in a large clinical database. We computed individual patient NLR and categorized patients by quartile of
this ratio. The association of NLR quartiles and 28-day mortality was assessed using multivariable logistic regression.
Secondary outcomes included mortality in the ICU, in-hospital mortality and 1-year mortality. An a priori subgroup
analysis of patients with versus without sepsis was performed to assess any differences in the relationship between
the NLR and outcomes in these cohorts.
Results: A total of 5,056 patients were included. Their 28-day mortality rate was 19%. The median age of the cohort
was 65 years, and 47% were female. The median NLR for the entire cohort was 8.9 (interquartile range, 4.99 to 16.21).
Following multivariable adjustments, there was a stepwise increase in mortality with increasing quartiles of NLR (first
quartile: reference category; second quartile odds ratio (OR) = 1.32; 95% confidence interval (CI), 1.03 to 1.71; third
quartile OR = 1.43; 95% CI, 1.12 to 1.83; 4th quartile OR = 1.71; 95% CI, 1.35 to 2.16). A similar stepwise relationship was
identified in the subgroup of patients who presented without sepsis. The NLR was not associated with 28-day mortality
in patients with sepsis. Increasing quartile of NLR was statistically significantly associated with secondary outcome.
Conclusion: The NLR is associated with outcomes in unselected critically ill patients. In patients with sepsis, there
was no statistically significant relationship between NLR and mortality. Further investigation is required to increase
understanding of the pathophysiology of this relationship and to validate these findings with data collected
prospectively.
with outcomes in patients with a number of different malignancies. The objective of this study was to assess the
relationship between NLR and mortality in a population of adult critically ill patients.
Methods: We performed an observational cohort study of unselected intensive care unit (ICU) patients based on
records in a large clinical database. We computed individual patient NLR and categorized patients by quartile of
this ratio. The association of NLR quartiles and 28-day mortality was assessed using multivariable logistic regression.
Secondary outcomes included mortality in the ICU, in-hospital mortality and 1-year mortality. An a priori subgroup
analysis of patients with versus without sepsis was performed to assess any differences in the relationship between
the NLR and outcomes in these cohorts.
Results: A total of 5,056 patients were included. Their 28-day mortality rate was 19%. The median age of the cohort
was 65 years, and 47% were female. The median NLR for the entire cohort was 8.9 (interquartile range, 4.99 to 16.21).
Following multivariable adjustments, there was a stepwise increase in mortality with increasing quartiles of NLR (first
quartile: reference category; second quartile odds ratio (OR) = 1.32; 95% confidence interval (CI), 1.03 to 1.71; third
quartile OR = 1.43; 95% CI, 1.12 to 1.83; 4th quartile OR = 1.71; 95% CI, 1.35 to 2.16). A similar stepwise relationship was
identified in the subgroup of patients who presented without sepsis. The NLR was not associated with 28-day mortality
in patients with sepsis. Increasing quartile of NLR was statistically significantly associated with secondary outcome.
Conclusion: The NLR is associated with outcomes in unselected critically ill patients. In patients with sepsis, there
was no statistically significant relationship between NLR and mortality. Further investigation is required to increase
understanding of the pathophysiology of this relationship and to validate these findings with data collected
prospectively.
Date Issued
2015-01-19
Date Acceptance
2014-12-23
Citation
Critical Care, 2015, 19
ISSN
1364-8535
Publisher
BioMed Central
Journal / Book Title
Critical Care
Volume
19
Copyright Statement
© 2015 Salciccioli et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,
unless otherwise stated.
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,
unless otherwise stated.
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Subjects
Science & Technology
Life Sciences & Biomedicine
Critical Care Medicine
General & Internal Medicine
ACUTE PHYSIOLOGY SCORE
LYMPHOCYTE RATIO
SEPTIC SHOCK
ILL PATIENTS
PREDICTS SURVIVAL
PANCREATIC-CANCER
PROGNOSTIC-FACTOR
MULTIPLE TRAUMA
SEVERE SEPSIS
BIOMARKERS
Publication Status
Published
Article Number
13