Selection of Appropriate Glomerular Filtration Rate Estimating Equation

Much effort has been made to improve the accuracy of plasma creatinine (Pcr) based glomerular filtration rate (GFR) estimating equations, and many equations have been published. In Mainland China, prior to the publication of the Modification of Diet in Renal Disease (MDRD) study equation, the main GFR estimating equation used was the Cockcroft-Gault equation. The MDRD equations were published in 1999, simplified in 2000, and re- expressed in 2006. That same year, the MDRD equations were modified for use in Chinese patients with chronic kidney disease (CKD). With the numerous GFR estimating equations available, which is the most appropriate, especially in Chinese patients with CKD? In this review, methods on how different equations can be compared will be discussed, the importance of calibration of Pcr will be emphasized, and some tricky issues on the development of these equations will be presented, which should be helpful in aiding our selection of the most appropriate equation to use.