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Related Experiment Video

Updated: Jun 9, 2026

Characterization of Sickling During Controlled Automated Deoxygenation with Oxygen Gradient Ektacytometry

Characterization of Sickling During Controlled Automated Deoxygenation with Oxygen Gradient Ektacytometry

Published on: November 5, 2019

Hemoglobin variability and mortality: confounding by disease severity.

Eric D Weinhandl¹, Yi Peng, David T Gilbertson

¹Minneapolis Medical Research Foundation, MN, USA. eweinhandl@cdrg.org

American Journal of Kidney Diseases : the Official Journal of the National Kidney Foundation

|August 31, 2010

Summary

Hemoglobin variability in hemodialysis patients showed a weak link to mortality after accounting for disease severity. This suggests hemoglobin level variability may have limited clinical use in predicting patient outcomes.

Related Experiment Videos

Last Updated: Jun 9, 2026

Characterization of Sickling During Controlled Automated Deoxygenation with Oxygen Gradient Ektacytometry

Characterization of Sickling During Controlled Automated Deoxygenation with Oxygen Gradient Ektacytometry

Published on: November 5, 2019

Area of Science:

Nephrology
Clinical Epidemiology
Outcomes Research

Background:

Hemoglobin level variability is linked to higher mortality and comorbidity in hemodialysis patients.
Accurate adjustment for disease severity is crucial for assessing this association.
Previous studies highlight the need for robust confounding control.

Purpose of the Study:

To investigate the association between hemoglobin level variability and mortality risk in hemodialysis patients.
To determine if this association persists after adjusting for disease severity.
To evaluate the clinical utility of hemoglobin level variability as a predictor.

Main Methods:

Retrospective cohort study of Medicare hemodialysis patients (n=133,246 to 24,999).
Hemoglobin variability measured using residual deviation from linear trend over 6 months.
Cox models analyzed 1-year mortality, adjusting for comorbid conditions and hospitalization.

Main Results:

Hemoglobin variability was positively associated with disease severity across all patient groups.
Unadjusted hazard ratios for mortality ranged from 1.08 to 1.32.
After adjusting for disease severity, hazard ratios for mortality became weak and inconsistent (1.01-1.07).

Conclusions:

The association between hemoglobin level variability and mortality risk is weak and inconsistent after adjusting for concurrent disease severity.
The clinical utility of hemoglobin level variability as a mortality predictor in hemodialysis patients may be limited.
Limitations include potential selection bias and residual confounding from comorbid conditions.