#3193 performance of the race-free ckd-epi creatinine-based egfr equation in a danish cohort with chromium-51-edta clearance measurements

Abstract Background and Aims In 2021, an updated estimated glomerular filtration rate (eGFR) equation based on serum creatinine, age, and sex, but without a coefficient for race (CKD-EPI21) was developed and recommended for clinical use. However, the performance of the new equation has yet to be examined among specific groups such as patients with cancer. Method We compared the performances of the CKD-EPI21 equation and the original creatinine-based eGFR equation assuming non-Black race (CKD-EPI09-NB) in patients ≥18 years of age with measured GFR ascertained by chromium-51-EDTA plasma clearance at Aarhus University Hospital in Denmark during 2010–2018. We examined bias, accuracy, precision (defined as the interquartile range of the absolute bias), and correct classification of chronic kidney disease (CKD) stages (GFR ≥60, 30–59, and <30 ml/min/1.73 m2) using the chromium-51-EDTA clearance as the reference standard. Furthermore, we assessed the performance of the equations in the total cohort while stratifying by CKD stage. We assessed the performance in the total cohort and in cohorts of cancer patients and potential living kidney donors. Results In this predominantly White population, the CKD-EPI21 equation performed slightly better than the CKD-EPI09-NB equation, both when examining the total cohort (N = 4,668) and when examining cohorts of cancer patients (N = 3,313) and potential living kidney donors (N = 239). In the total cohort, the CKD-EPI21 equation demonstrated lower median absolute bias (−0.2 versus −4.4 ml/min/1.73 m2), higher accuracy (72% versus 70%) as well as equal precision (25 versus 25 ml/min/1.73 m2) and correct classification of CKD stages (86% versus 85%) when compared with the CKD-EPI09-NB equation. When we stratified by CKD stage, the CKD-EPI09-NB equation performed slightly better than the CKD-EPI21 equation among patients with a GFR < 60 ml/min/1.73 m2. Conclusion In a selected cohort of Danish patients with measured GFR, the CKD-EPI21 equation performed slightly better than the CKD-EPI21-NB equation except for patients with a GFR < 60 ml/min/1.73 m2.