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Racial Bias in eGFR Kidney Function Algorithm Delays Treatment for Black Patients
CriticalA widely-used kidney function algorithm systematically overestimated kidney health in Black patients for over two decades, delaying critical transplant referrals and treatment for millions.
Category
Bias
Industry
Healthcare
Status
Resolved
Date Occurred
Jan 1, 1999
Date Reported
Jun 1, 2020
Jurisdiction
US
AI Provider
Other/Unknown
Model
Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFR equation
Application Type
embedded
Harm Type
physical
People Affected
3,000,000
Human Review in Place
No
Litigation Filed
Yes
Litigation Status
settled
racial_biashealthcare_algorithmkidney_diseaseclinical_decision_supporthealth_equityalgorithmic_discrimination
Full Description
The estimated glomerular filtration rate (eGFR) equation, developed by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) in 2009 and its predecessor equations dating back to 1999, incorporated a race coefficient that increased calculated kidney function for Black patients by approximately 16%. This adjustment was based on assumptions about higher average muscle mass in Black individuals, which affects creatinine levels used in the calculation. The algorithm became standard practice across virtually all U.S. healthcare systems and was embedded in electronic health records and laboratory reporting systems.
The racial adjustment had profound clinical consequences, as eGFR scores directly determine when patients qualify for kidney transplant waiting lists, specialist referrals, and certain medications. Black patients needed significantly worse actual kidney function before the algorithm would indicate severe disease, systematically delaying their access to life-saving interventions. Research published in 2020 and 2021 demonstrated that removing the race coefficient would have made an estimated 3 million Black Americans immediately eligible for earlier nephrology referrals and hundreds of thousands eligible for transplant listing.
The bias was first systematically challenged in 2020 when nephrologists at the University of Washington and other institutions published studies showing the discriminatory impact. Dr. Vanessa Grubbs and colleagues demonstrated that the race-based equation perpetuated health disparities and was not scientifically justified. The National Kidney Foundation and American Society of Nephrology formed a joint task force to address the issue, leading to new race-neutral equations being recommended in 2021.
Major healthcare systems including Vanderbilt University Medical Center, Beth Israel Deaconess Medical Center, and the University of California system began removing race from their eGFR calculations in 2021. However, implementation has been uneven, with some systems slower to adopt changes. The incident highlights how algorithmic bias can become entrenched in medical practice for decades, affecting millions of patients before being recognized and addressed. The financial impact on affected patients includes delayed treatment costs, progression to more expensive dialysis, and reduced quality of life from delayed transplants.
Root Cause
The eGFR algorithm incorporated a race coefficient that artificially inflated kidney function estimates for Black patients by approximately 16%, based on outdated assumptions about muscle mass differences. This systemic bias was embedded in clinical decision-making tools nationwide.
Mitigation Analysis
Algorithm auditing for demographic bias could have identified disparate impacts across racial groups. Regular outcome monitoring comparing transplant referral rates and treatment timing by race would have revealed the systematic delays. Implementation of bias testing requirements for clinical algorithms and mandatory periodic reviews of embedded demographic variables could prevent such widespread harm.
Litigation Outcome
Multiple class action lawsuits filed against healthcare systems and kidney organizations, with several settlements reached requiring algorithm changes and compensation for affected patients.
Lessons Learned
Clinical algorithms must be regularly audited for demographic bias and disparate outcomes. Historical assumptions about biological differences between racial groups require ongoing scrutiny as medical understanding evolves.
Sources
Hidden in Plain Sight — Reconsidering the Use of Race Correction in Clinical Algorithms
New England Journal of Medicine · Aug 27, 2020 · academic paper
A medical algorithm has been adjusting care for Black patients. There's a push to change that.
The Washington Post · Sep 24, 2021 · news