Less bias with the 2021 CKD-EPI equation
The researchers compared the three eGFR equations with their respective measured GFR values by two metrics: bias, defined as the median difference between measured and estimated GFR; and the percentage of eGFR values that fell within 30% of the corresponding measured GFR value.
The results showed that bias was lowest using the 2021 CKD-EPI equation, with an overall median difference of 0.5 mL/min per 1.73 m2. This compared with median differences of 7.2 with the CKiD U25 equation and 4.9 mL/min per 1.73 m2 with the EKFC equation. The disparity in bias was greatest among those with eGFR values in the range of 60-90 mL/min per 1.73 m2 and was also greatest for those 18-25 years old.
The CKD-EPI equation results also showed the greatest consistency of bias across the entire 18- to 40-year-old range. Between-group differences were small for the percentage of eGFR values that fell within 30% of measured GFR, with all three equations scoring in the range of 88%-90%.
The study received no commercial funding. Dr. Inker is a consultant to Diamtrix and her department receives research funding from Chinook, Omeros, Reata, and Tricida. Dr. Coresh is a consultant to Healthy.io and SomaLogic and he has an ownership interest in Healthy.io.