Current equations used to estimate glomerular filtration rate (eGFR) incorporate age, sex, and race—despite race in these equations being used as a social, not biological, construct. To address this, researchers developed new eGFR equations that exclude race, using large development and validation data sets. When validated, existing creatinine-based equations overestimated kidney function in Black individuals and slightly in non-Black individuals. Removing the race adjustment led to underestimation in Black participants. A new equation using age and sex alone still showed racial discrepancies. However, a combined creatinine–cystatin C equation without race demonstrated improved accuracy and reduced disparities between racial groups.

These race-free creatinine–cystatin C equations were more precise than creatinine-only formulas and produced smaller differences in estimated kidney function between Black and non-Black individuals. While switching to new creatinine-only equations raised the projected prevalence of chronic kidney disease (CKD) among Black adults, the creatinine–cystatin C models offered more balanced prevalence estimates across groups. These findings support adopting race-neutral equations using both biomarkers to improve equity and clinical accuracy in CKD diagnosis and care.

Reference: Inker LA, Eneanya ND, Coresh J, et al. New Creatinine- and Cystatin C-Based Equations to Estimate GFR without Race. N Engl J Med. 2021;385(19):1737-1749. doi: 10.1056/NEJMoa2102953.