CST3 and chronic kidney disease: The accuracy of this estimating equation has long been contemplated and assessed by the members of the CKD-EPI Collaboration who also developed a 2012 version based on creatinine and cystatin C. In general, equations with multiple endogenous filtration markers are considered more precise than a single filtration marker counterpart.18,19 Also, a substantial proportion of the sampled population with reported renal dysfunction or elevated SCr did not report their gender, race, age, education, or income.