Removal of ethnicity adjustment for creatinine-based estimated glomerular filtration rate equations

Creatinine-based estimated glomerular filtration rate equations (eGFRcreatinine) are used to measure excretory kidney function in clinical practice. Despite inter and intra-patient variability, eGFRcreatinine has excellent clinical utility and provides the basis for the classification system for chronic kidney disease (CKD), for kidney function monitoring, treatment interventions and referral pathways. The 4-variable modification of diet in renal disease (MDRD) eGFRcreatinine equation was introduced in 2000 and recommended by the National Institute for Health and Care Excellence (NICE) in 2008. Subsequently, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFRcreatinine equation was introduced in 2009 and is more accurate than MDRD in patients with mild and moderate CKD. In 2014, NICE recommended that CKD-EPI eGFRcreatinine replace MDRD eGFRcreatinine in routine clinical practice across England. Both equations originally incorporated adjustments for age, gender and ethnicity. However, the evidence for ethnicity adjustment has been increasingly questioned, and in 2021 NICE recommended that kidney function should be estimated by CKD-EPI eGFRcreatinine without using ethnicity adjustment. Recently, a CKD-EPI equation has been presented without ethnicity adjustment; however, this has not been validated outside of North America and NICE continues to recommend CKD-EPI 2009. We review the status of eGFRcreatinine in clinical practice, including the limitations of eGFRcreatinine and the rationale for removal of ethnicity adjustment and the potential impact of this change on clinical care for patients with kidney disease.