CKD-EPI Cystatin C was developed in 2012 to estimate GFR from serum cystatin C, age, and sex. The equation has similar accuracy to the CKD-EPI Creatinine 2009 Equation. The advantage of the CKD-EPI Creatinine-Cystatin C 2012 equation has over the creatinine-based equation is that it is less subject to the effects of age, sex, and race. We found that in the development and internal-validation data sets, the addition of race as a variable did not improve the performance of the CKD-EPI Creatinine-Cystatin C 2012 equations in the black subgroup. Given the difficulties in assigning race and the lack of information about race in laboratory and administrative database, a GFR estimating equation that does not require race may be more generalizable across populations and could generally facilitate the use of estimated GFR in clinical practice, research, and public health programs. Furthermore, the data suggests that cystatin C could be used as a confirmatory test for chronic kidney disease and also to obtain a more accurate estimation of GFR in patients with muscle wasting or chronic illness. The table shows the equation expressed as a separate equation by level of serum creatinine, sex and race. The footnote at the bottom of the tables shows the equation expressed as a single equation.

##### CKD-EPI creatinine-cystatin C equation

CKD-EPI Creatinine-Cystatin C was developed in 2012 to estimate GFR from serum creatinine, cystatin C, age, sex, and race. The equation had similar bias to the creatinine or cystatin C equations but was more precise and therefore had greater overall accuracy. The table shows the equation expressed as a separate equation by level of serum creatinine, sex and race. The footnote at the bottom of the tables shows the equation expressed as a single equation.

Last Updated: July 2014