Research Appraisalobservational

Associations between haemoglobin-to-red cell distribution width ratio and mortality in intracerebral haemorrhage: a population-based analysis of the MIMIC-IV database

Journal of global healthChen, Bo-An, Lin, Shin-Nan, Wei, Kuo-Chen et al.17 Apr 2026DOI

Clinical Snapshot

70CEBM
Evidence: Moderateobservational

PICO Framework

P — PopulationAdults (≥18 years) with intracerebral haemorrhage admitted to intensive care units
I — InterventionHigher haemoglobin-to-red cell distribution width ratio (HRR) quartiles
C — ComparatorLowest HRR quartile (Q1)
O — Outcomes28-day and 1-year all-cause mortality

Bottom Line

This large retrospective cohort study suggests that the haemoglobin-to-red cell distribution width ratio (HRR) may serve as a prognostic biomarker in ICU patients with intracerebral haemorrhage. Higher HRR values were associated with significantly lower 28-day and 1-year mortality risks, with the highest quartile showing 33-44% relative risk reduction. While the findings are promising for early risk stratification using readily available laboratory parameters, the study's retrospective design, lack of external validation, and unclear follow-up completeness limit immediate clinical application. The biological plausibility linking haematological parameters to ICH outcomes requires further investigation. Prospective validation studies with standardised HRR cut-offs and comparison to established ICH prognostic scores are needed before incorporating HRR into routine clinical decision-making. Australian clinicians should await external validation before adopting HRR for prognostication in stroke units.

Evidence: Moderate

Key Findings

  • P Value: Not explicitly reported for primary comparisons

  • Effect Size: Q4 vs Q1: aHR 0.67 (28-day), aHR 0.56 (1-year)

  • Primary Outcome: 28-day and 1-year all-cause mortality

  • Nnt Or Sensitivity: Hazard ratios suggest 33-44% relative risk reduction in highest HRR quartile

  • Confidence Interval: 28-day: 95% CI 0.49-0.90; 1-year: 95% CI 0.42-0.75

Clinical Application

Highly feasible - uses routine laboratory parameters (haemoglobin, RDW) available in all hospitals Relevant to Australian ICUs; HRR calculation uses standard pathology tests covered by Medicare. Could complement existing stroke unit protocols and align with National Stroke Foundation guidelines ICU patients with intracerebral haemorrhage requiring intensive monitoring

Abstract

BACKGROUND: Intracerebral haemorrhage (ICH) is a leading cause of mortality and morbidity worldwide. Identifying early prognostic biomarkers is crucial to optimise clinical management of critically ill patients with ICH. The haemoglobin-to-red cell distribution width ratio (HRR) has recently emerged as a potential predictor in various critical illnesses, but its role in ICH remains unclear. This study aimed to evaluate associations between HRR and mortality in patients with ICH. METHODS: This retrospective cohort study included the data of adults (≥18 years) extracted from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database (version 1). HRR was calculated from the first available haemoglobin and RDW measurements within one day of each other. Patients were categorised into HRR quartiles. The primary outcomes were 28-day and 1-year all-cause mortality. Associations were assessed using Cox proportional hazards models. RESULTS: The data of 1915 patients (mean age 67.5 years) were analysed retrospectively. After adjusting for possible confounders, compared with the lowest HRR quartile (Q1), patients in Q3 and Q4 had significantly lower 28-day mortality (Q3: adjusted hazard ratio (aHR) = 0.72; 95% CI = 0.54, 0.97; Q4: aHR = 0.67; 95% CI = 0.49, 0.90). Similarly, higher HRR quartiles were associated with reduced 1-year mortality risk (Q3: aHR = 0.64; 95% CI = 0.49, 0.84; Q4: aHR = 0.56; 95% CI = 0.42, 0.75). CONCLUSIONS: Lower HRR at admission is independently associated with higher short-term and long-term mortality in ICU patients with ICH. HRR may serve as a candidate prognostic biomarker for early risk stratification in this high-risk population. Further prospective studies are warranted to confirm these findings.

References

  1. 1.Chen, B.-A., Lin, S.-N., Wei, K.-C., Hsieh, Y.-Y., Yan, J.-L., Chen, M.-Y., Kuo, Y.-H., Chen, Y.-Y., & Chen, P.-Y. (2026). Associations between haemoglobin-to-red cell distribution width ratio and mortality in intracerebral haemorrhage: a population-based analysis of the MIMIC-IV database. Journal of Global Health, 16, 04065. https://doi.org/10.7189/jogh.16.04065
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