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A Task Force formed by the National Kidney Foundation (NKF) and the American Society for Nephrology (ASN) recommends use of the CKD-EPI creatinine equation refit without the race variable across all laboratories in the United States in estimating glomerular filtration rate (eGFR).

This follows calls to re-evaluate race as part of clinical decision-making, recognizing its social – and not biological – nature, and the need to advance health equity and social justice. The Task Force sought to identify eGFR approaches that would integrate filtration marker/assay availability and standardization, ease of implementation by laboratories and in clinical practice, diversity of population from which the equation was derived, equation performance, avoidance of foreseeable adverse clinical consequences, and patient centeredness.

The recommended equation was developed without incorporating race in its calculation and was derived from a population cohort that had diversity in race, age, and sex. It also uses variables readily available to laboratories for easy implementation, as serum creatinine is a common test in many laboratories and on high-throughput analyzers; this contrasts with another marker, Cystatin C, which is less widely available.

Regarding the potential consequences of changing the estimation approach, this would not disproportionately affect any one racial group with the use of the recommended equation. There is less change in the estimated GFR and reduced bias in Black individuals, with similar differential bias between Black and non-Black individuals, in terms of chronic kidney disease (CKD) screening and detection, nephrology referral, radiographic diagnostic assessment, and risk of mortality, kidney failure with replacement therapy, and incident CKD. This would also potentially support processes that patients desire, such as earlier CKD detection, transparent communication of this detection with patients, tracking of eGFR trajectory over time, rapid referral to nephrology, and prompt transplant referral for individuals with advanced CKD.

It has also shown acceptable performance characteristics in terms of bias and accuracy compared to the current eGFR approach. However, other approaches using two or more filtration markers showed improved accuracy, with none showing poor performance. Hence, the Task Force also recommends increased, routine, and timely use of Cystatin C, and combining filtration markers to provide more accurate first-line or confirmatory testing. Encouraged as well are further research on GFR estimation using new endogenous filtration markers.

The challenge is in prompt and unified implementation and uptake in clinical and laboratory practice. This will require a concerted effort from multiple stakeholders – national and local laboratories, policymakers, regulators, and health care providers. Despite these hurdles, this aims to promote efforts to study GFR estimation in different populations and eliminating the effects of race and ethnic disparities in kidney disease. Through these recommendations, the practice of medicine is catching up with the race towards a more equitable system.

Access the full article through this link: https://jasn.asnjournals.org/content/32/12/2994

For more information on this new estimation approach, this is the study from which it was derived: https://www.nejm.org/doi/pdf/10.1056/NEJMoa2102953?articleTools=true.

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References :

Delgado C, Baweja M, Crews DC, Eneanya ND, Gadegbeku CA, Inker LA, Mendu ML, Miller WG, Moxey-Mims MM, Roberts GV, St. Peter WL, Warfield C, Powe NR. (December 2021). A Unifying Approach for GFR Estimation: Recommendations of the NKF-ASN Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease. Am J Kidney Dis 79(2):268-288. DOI: https://doi.org/10.1681/ASN.2021070988.