Implementation of Race‑Free eGFR Estimation for African‑American Patients

Guideline Recommendations

• The NKF‑ASN Task Force issued a strong recommendation that the 2021 CKD‑EPI creatinine equation be used without a race variable for all U.S. adults, replacing race‑based adjustments. [1][2]
• The KDOQI Work Group endorses the use of the race‑free 2021 CKD‑EPI eGFRcr, the 2021 CKD‑EPI eGFRcr‑cys, and the 2012 CKD‑EPI eGFRcys equations for adult patients. 2
• KDIGO Practice Point 1.2.4.2 explicitly states that race should be avoided in eGFR calculations. 2

Equation Characteristics

• The 2021 CKD‑EPI creatinine equation does not include race in either its calculation or its reporting. [1][2]
• Validation studies show the equation has acceptable performance characteristics across diverse populations. 1
• Compared with prior race‑based formulas, the race‑free equation reduces differential bias between Black and non‑Black individuals. [3][4]

Clinical Testing Recommendations

First‑Line Testing

• For routine eGFR estimation in all adults, use the 2021 CKD‑EPI creatinine equation (race‑free). This is supported by multiple guideline bodies. [1][2]5

Confirmatory Testing

• In patients at risk for or with established CKD, add cystatin C measurement and apply the 2021 CKD‑EPI creatinine‑cystatin C equation (race‑free) for confirmation, which improves accuracy and narrows differences between Black and non‑Black participants. [1][5]
• Cystatin C is especially valuable in individuals with low muscle mass, where creatinine‑based eGFR estimates are less reliable. 5

Practice Points

• Do not report two eGFR values (one with race and one without) or label them as “high muscle mass” versus “low muscle mass”; the Task Force found no evidentiary basis for such dual reporting, which adds subjectivity and confusion. [1][4]

Implementation Guidance

• Clinical laboratories should adopt the race‑free 2021 CKD‑EPI equations and report eGFR together with the corresponding filtration marker concentrations (creatinine and/or cystatin C). 2
• The race‑free approach eliminates systematic disadvantages for Black individuals while preserving accuracy across all populations. 1

Expected Clinical Impact

• Applying the race‑free equations will identify more Black patients with eGFR < 60 mL/min/1.73 m², leading to earlier nephrology referral, initiation of kidney‑protective therapies, and timely transplant evaluation. 3

Racial Disparities in Kidney Disease Diagnosis and Transplant Eligibility

Evidence of Delayed Diagnosis

• The National Kidney Foundation recommends that Black individuals receive eGFR values without the race coefficient, as including it results in systematically higher eGFR values, delaying diagnosis of kidney disease and eligibility for kidney transplant, with approximately 10-16% higher eGFR values compared to non-Black individuals with identical age, sex, and serum creatinine levels 6, 7, 8
• Approximately 2 million Black adults in the US would be reclassified to having CKD if race were removed from the eGFR calculation, according to the American Journal of Kidney Diseases 6, 7

Evidence of Delayed Transplant Eligibility

• The NKF-ASN Task Force quantified that removing the race coefficient would increase the number of Black adults meeting transplant referral threshold by approximately 290,000 individuals, a 29% increase, as reported by the National Kidney Foundation 6, 7

Clinical Consequences Beyond Transplant

• The National Kidney Foundation documented that race-based eGFR creates systematic disadvantages for Black individuals, including nephrology referral delays, with 260,000 fewer Black adults meeting referral thresholds when race is included 6, 7
• The American Journal of Kidney Diseases found that fewer Black patients qualify for kidney-protective medications, such as ACE inhibitors and SGLT2 inhibitors, due to delayed diagnosis of CKD 8, 9

The 2021 Solution

• The NKF-ASN Task Force recommended adopting the CKD-EPI 2021 equation without race, which eliminates the race coefficient while maintaining accuracy, reducing differential bias between Black and non-Black individuals and providing earlier identification of kidney disease in Black patients 6, 10, 11
• The National Kidney Foundation reported that this change improves equity in transplant access without disadvantaging other groups 6, 11

Implementation of Race‑Free GFR Estimation for African‑American Patients

Primary Recommendation – NKF‑ASN Task Force (2022)

• The NKF‑ASN Task Force issued a strong recommendation to adopt the 2021 CKD‑EPI creatinine equation without a race variable (CKD‑EPIcr_R) for all adult patients in U.S. laboratories immediately. 12, 13, 14
• The race‑free equation maintains acceptable performance across diverse populations while markedly reducing differential bias between Black and non‑Black individuals. 12, 15
• It is readily available to all laboratories and does not require new assays or infrastructure. 12, 14

Confirmatory Testing Strategy – NKF‑ASN Task Force (2022)

• For patients at risk for or with established CKD, add a cystatin C measurement and use the 2021 CKD‑EPI creatinine‑cystatin C equation without race (CKD‑EPIcr‑cys_R). 13, 15
• Combining creatinine and cystatin C provides greater accuracy than either marker alone and eliminates the need for any race‑based adjustment. 13, 15

Laboratory Reporting Guidelines – NKF‑ASN Task Force (2022)

• Report eGFR using the race‑free 2021 CKD‑EPI equation. 12
• Display serum creatinine values to two decimal places to improve precision. 15
• Use non‑indexed eGFR values (mL/min) when making drug‑dosing decisions. 15
• In patients with obesity, consider de‑indexing GFR for medication dosing because indexed eGFR may underestimate true GFR. 12, 16

Clinical Decision‑Making – NKF‑ASN Task Force (2022)

• Do not base major clinical decisions on a single eGFR result; confirm with repeat testing. 12, 15
• Monitor eGFR trends over time, employing more frequent testing when needed. 12, 15
• Incorporate albuminuria assessment as recommended by KDIGO CKD guidelines to complement eGFR information. 15
• For critical decisions, use confirmatory testing with cystatin C‑based equations or clearance measurements. 15
• When high precision is required, consider direct GFR measurement using exogenous filtration markers. 15

Guideline Consensus & Evidence Strength – NKF‑ASN Task Force (2022)

• The consensus strongly favors race‑free equations, emphasizing that the prior race‑based approach created systematic disadvantages for Black individuals in accessing nephrology care, transplant evaluation, and kidney‑protective therapies. 12, 13
• The Task Force prioritized reducing differential bias and promoting health equity over preserving the statistical properties of older race‑based equations. 12, 14

Assay Recommendations – NKF‑ASN Task Force (2022)

• Laboratories should discontinue Jaffe reaction assays for serum creatinine and adopt enzymatic assays to reduce variability and improve eGFR accuracy. 15
• Standardize cystatin C assays to facilitate broader implementation of confirmatory testing. 13

Race‑Free eGFR Estimation for Black Women

Recommendation Overview

Rationale for Black Women

Confirmatory Testing Strategy

Laboratory Reporting Standards

Clinical Decision‑Making

Implementation Pitfalls

Evidence Quality and Consensus