The CKD-EPI creatinine equation of 2009 is based on the same four variables as the MDRD Study equation, but uses a 2-slope spline to model the relationship between estimated GFR and serum creatinine, and a different
relationship for age, sex and race. The equation was reported to perform better and with less bias than the MDRD Study equation, especially in patients with higher GFR. This results in reduced misclassification of CKD. Clinical laboratories now report the
estimated GFR using the CKD-EPI creatinine equation. A CKD-EPI creatinine and cystatin C equation was developed in 2012. In 2021 the CKD-EPI creatinine, and the creatinine with cystatin C equations were modified so that the race coefficient is no longer necessary. .
The CKD-EPI creatinine equation of 2012 is:
Ref: Inker LA, Eneanya ND, et al. ANew Creatinine- and Cystatin C–Based Equations to Estimate GFR without Race. N Engl J Med N Engl J Med 2021; 385:1737-1749