The equation to estimate glomerular filtration rate: the MDRD equation and CKD-EPI equation

Abstract

The assessment of kidney function is an important part of medical practice for detection of chronic kidney disease (CKD), evaluation of rate of progression and its severity, and the appropriate management including renal replacement therapy (RRT). It is essential to assess overall health such as selecting the correct dosage for drugs which are excreted by the kidneys. The gold standard for estimating glomerular filtration rate (GFR) is costly, burdensome and not available in many places. Several formulas for estimating GFR have been developed. The most widely studied of these are the Modification of Diet in Renal Disease (Modification of Diet in Renal Disease Study; MDRD equation) and the CKD-EPI equation. Both of these equations provide a clinically useful to estimate GFR and easy to implement since they require only serum creatinine, sex, age and race. However, it has been shown previously that the MDRD Study equation underestimates the measured GFR (mGFR) at eGFR >60 mL/min/1.73 m2. The CKD-EPI equation is shown in less bias than the MDRD Study equation is in many subgroups. Currently, this equation should be replaced the MDRD Study equation for general clinical use and can be reported throughout the GFR range. Further study should be investigated which equation is the most accurate in Thai population.