On the Basis of Race: The Utility of a Race Factor in Estimating Glomerular Filtration

Background: Glomerular filtration rate (GFR) is a measure of the combined rate of filtration of all functional nephrons in the kidney. Measurement of GFR is used in the clinic to detect, stratify, and monitor progression of kidney dysfunction, and also serves as a prognostic tool for staging chronic kidney disease (CKD). The gold standard method for measuring GFR is by plasma or urine clearance of exogenous filtration markers, but this is not feasible in routine clinical practice. The most commonly used method to assess GFR is using equations for estimated GFR (eGFR). Content: Addition of a race factor to eGFR equations has been recommended to optimize performance for Black individuals. Here, we review the basis of the race-based equation and assess its utility and widespread applicability. Summary: Although evidence supporting the performance of a race factor exists in the unique populations in which these estimation equations were derived, more studies are needed to assess the need, or lack thereof, for race factors for all ethnicities. Furthermore, ethnicity is complex and likely cannot be qualified with a 2-level descriptor.