The removal of race-based adjustments in eGFR calculations aims to improve accuracy and equity in kidney disease diagnosis for African Americans.
The Evolution of eGFR Calculations and Race
The estimated glomerular filtration rate, or eGFR, is a critical measurement used worldwide to assess kidney function. It estimates how well the kidneys filter waste from the blood. Traditionally, eGFR calculations included a race-based coefficient for African Americans, which raised significant concerns over accuracy and fairness.
This race adjustment was introduced decades ago due to observed differences in average serum creatinine levels between Black and non-Black populations. The assumption was that African Americans had higher muscle mass on average, leading to naturally higher creatinine levels independent of kidney function. Therefore, a multiplier was applied to their eGFR results to avoid underestimating kidney function.
However, this approach has been heavily criticized for oversimplifying complex biological and social factors and potentially delaying diagnosis or treatment for Black patients. The question now is clear: eGFR For African Americans- What Changed?
Why the Race Adjustment Was Problematic
The race-based adjustment in eGFR calculations led to several unintended consequences:
- Delayed Diagnosis: By inflating eGFR values for African Americans, some patients appeared healthier than they truly were, leading to delays in identifying chronic kidney disease (CKD).
- Treatment Inequities: Higher eGFR readings could postpone referrals for specialist care or eligibility for kidney transplants.
- Reinforcement of Racial Bias: Using race as a biological proxy ignored socioeconomic factors, access to care, and genetic diversity within racial groups.
Medical experts argued that race is a social construct rather than a precise biological variable. Thus, relying on it within clinical algorithms risks perpetuating health disparities instead of reducing them.
The Shift Toward Race-Neutral eGFR Equations
In recent years, major health organizations and researchers have pushed for removing race from eGFR calculations. The National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) formed a task force that reviewed evidence and recommended adopting new equations without race adjustments.
The new CKD-EPI 2021 equation estimates GFR without considering race but instead incorporates serum creatinine along with other factors such as age and sex. This update aims to provide more equitable assessments across all populations.
Several laboratories across the United States have already transitioned to these new formulas. This change means more accurate detection of CKD among African Americans and earlier interventions that could save lives.
How Does the New Equation Work?
The updated equation uses the same biomarkers but removes the multiplier previously applied based on racial identity. Instead, it relies solely on measurable clinical factors:
| Factor | Previous Equation (with Race) | New Equation (Race-Neutral) |
|---|---|---|
| Serum Creatinine | Used with a race coefficient multiplier (~1.16 for Black patients) | Used directly without any racial adjustment |
| Age | Included as continuous variable | Included as continuous variable |
| Sex | Included as binary variable | Included as binary variable |
Removing the race factor reduces complexity while improving fairness in interpreting kidney function results.
The Impact on African American Patients
African Americans are disproportionately affected by chronic kidney disease and end-stage renal failure compared to other racial groups. The previous race-adjusted eGFR often masked early signs of kidney damage by producing inflated filtration rates.
Since switching to race-neutral equations:
- Earlier Detection: More African American patients are now identified at earlier stages of CKD.
- Treatment Access: Patients gain timely referrals to nephrologists and eligibility for transplant listings sooner.
- Better Outcomes: Early interventions can slow disease progression, reduce complications, and improve survival rates.
This shift also encourages clinicians to consider social determinants of health rather than relying on simplistic racial categories when assessing patient risk.
The Challenges of Transitioning Away From Race-Based Adjustments
While removing race from eGFR calculations is an important step forward, it’s not without challenges:
- Lack of Awareness: Some healthcare providers remain unfamiliar with the updated guidelines or hesitate to change established practices.
- Labs Updating Protocols: Not all laboratories have fully adopted the new equations yet, causing inconsistent reporting.
- Pediatric and Special Populations: More research is needed on how these changes affect children or patients with unusual muscle mass.
- Avoiding Overdiagnosis: Some worry that eliminating race adjustments might lead to overdiagnosis or unnecessary anxiety among patients.
Despite these hurdles, most experts agree that the benefits outweigh potential drawbacks when it comes to equity in healthcare.
The Science Behind Creatinine and Kidney Function Testing
Creatinine is a waste product generated from muscle metabolism excreted by kidneys at a relatively steady rate. Measuring serum creatinine levels gives insight into how efficiently kidneys filter blood.
However, creatinine levels vary naturally due to:
- Muscle Mass: Larger muscle mass produces more creatinine.
- Age: Muscle mass declines with aging.
- Diet & Hydration: Intake of meat or dehydration can affect serum creatinine temporarily.
Because muscle mass varies widely among individuals regardless of race, using race as a proxy became problematic over time. It failed to capture individual variability accurately.
Alternatives like cystatin C—a protein filtered by kidneys independent of muscle mass—have gained interest but are not yet universally adopted due to cost and availability limitations.
The Role of Social Determinants in Kidney Health Disparities
Kidney disease disparities among African Americans stem from complex social factors:
- Lack of Access: Limited access to quality healthcare delays diagnosis and treatment.
- Socioeconomic Status: Poverty increases risk factors like hypertension and diabetes.
- Diet & Environment: Food deserts and environmental toxins contribute to poor kidney health.
- Mistrust in Healthcare System: Historical abuses lead some patients to delay seeking care.
Correcting medical algorithms alone won’t fix these systemic issues but is an essential step toward equitable care.
The Timeline: How Did This Change Come About?
The path toward removing race from eGFR calculations unfolded over several years:
- Epidemiological Studies (1990s-2010s): Research showed differences in average serum creatinine but also highlighted limitations of using race broadly.
- Criticism Mounts (2010s): Medical ethicists questioned racial adjustments’ validity; advocacy groups called attention to disparities caused by these formulas.
- NKF-ASN Task Force Formation (2020): Leading nephrology organizations convened experts to evaluate evidence critically.
- KDOQI Guidelines Update (2021): New recommendations endorsed use of CKD-EPI equation without race coefficients for adults aged ≥18 years.
- Labs Begin Implementation (2021-Present): Many clinical labs started transitioning reporting standards accordingly.
- Broad Clinical Adoption (Ongoing): Hospitals, clinics, insurers update protocols; continuous education efforts underway worldwide.
This timeline reflects growing recognition that precision medicine demands moving beyond simplistic racial categories toward individualized assessments.
A Closer Look at CKD Staging With New Equations
Chronic kidney disease staging depends heavily on accurate eGFR values:
| CKD Stage | Description (eGFR mL/min/1.73m²) |
|---|---|
| Stage 1 | Normal or high function: ≥90 with other markers present |
| Stage 2 | Mild decrease: 60–89 |
| Stage 3a | Mild-moderate decrease: 45–59 |
| Stage 3b | Moderate-severe decrease:30–44 |
| Stage 4 | Severe decrease:15–29 |
| Stage 5 | Kidney failure:<15 or dialysis required |