Evidence map›Paper›PMID 41890439›Full record

ArticleAnnals of intensive care2026

Systematic review, meta-analysis, and meta-regression of the association of serial leukocyte counts in critically ill patients and mortality.

Nishkantha Arulkumaran, Fiona Dewar, Gareth Ambler, Maria Del Pilar Arias Lopez, Claudia Dos Santos, Jan J De Waele, Jeffrey Lipman, José-Artur Paiva, Jean-Francois Timsit

Abstract read
In one paragraph

Article in Annals of intensive care, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Nishkantha ArulkumaranBloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, United Kingdom.
Fiona DewarBloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, United Kingdom.
Gareth AmblerDepartment of Statistical Science, University College London, London, United Kingdom.
Maria Del Pilar Arias LopezPaediatric Intensive Care Unit, Hospital de Niños Ricardo Gutierrez Buenos Aires, Argentine Society of Intensive Care, Management, Quality and Data Committee Buenos Aires, Argentina.
Claudia Dos SantosThe Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto, ON, Canada.
Jan J De WaeleDepartment of Intensive Care Medicine, Ghent University Hospital, Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
Jeffrey LipmanJamieson Trauma Institute, Royal Brisbane and Women's Hospital, The University of Queensland.
José-Artur PaivaIntensive Care Medicine Service, Unidade Local de Saúde São João, Alameda Professor Hernani Monteiro, 4200-319 Porto, Faculty of Medicine, University of Porto, Infection and Sepsis Research and Development Group, Portugal.
Jean-Francois TimsitAssitance Publique Hôpitaux de Paris, Bichat Hospital, Medical and Infectious Diseases ICU (MI2), France.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Serial leukocyte counts have been investigated as a prognostic marker in critical illness. Our aim was to explore which immune cell type (total leukocytes, neutrophils, lymphocytes or neutrophil: lymphocyte ration (NLR)) best predicted mortality in critically ill patients. To address this, we conducted a systematic review, meta-analysis, and meta-regression of studies published within the past 10 years, archived on PubMed and Embase. Only studies reporting immune cell counts in critically ill patients on admission and within the subsequent week were included. Meta-regression was conducted to assess the effect of illness severity (reflected by study mortality rate) and underlying diagnosis (with 'general ICU patients' as a reference group) on the difference between immune cell counts between survivors and non-survivors. Meta-analysis and meta-regression were performed using Stata (version 19.5, StataCorp) and data presented as mean difference with (95% confidence intervals). Results: Thirty studies including 26,441 reporting patient mortality were included. Neutrophil: lymphocyte ratio (NLR) best predicted mortality and was lower among survivors at on days 0-1 (-0.29 (-0.45 to -0.12), p = 0.001), 2-4 (-1.02 (-1.57 to -0.48), p < 0.001), and 5-7 (-0.69 (-1.00 to -0.38), p < 0.001). Lymphocyte count was higher at equivalent time points. Meta-regression of NLR suggest that heterogeneity between studies was partly explained by underlying illness severity on days 0-1 (mean difference decreases by 0.13 (0.05, 0.20) for a 10% increase in mortality, p = 0.001), but not at other time points. Underlying diagnosis did not explain heterogeneity between studies. We were unable to perform a meta-analysis investigating the association between leukocyte counts and secondary infections as only three studies reported this data. Conclusion: A higher NLR count was associated with increased mortality throughout the first week of critical illness. Further work is required to define of cut- off values using an ordinal scale of lymphocyte count that accurately reflects immune dysfunction and risk of mortality. PROSPERO registration number: : CRD42024514115.

Indexed as

Critical illnessLeukocyteLymphocyteMortalityNeutrophil

Identifiers

PMID41890439
PMCPMC13015758

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.