Background: Three equations have been often used to estimate glomerular filtration rate (GFR), namely, Modification of Diet in Renal Disease (MDRD), MDRD for Chinese (MDRDc), and Cockcroft-Gault (CG), for the purpose of screening individuals with chronic kidney disease (CKD). However, neither of these equations has been tested in a large Asian population. The aim of this study was to determine which equations were suitable for screening CKD in a large Taiwanese population.
Methods: The applicability of the three equations was analyzed among 32,542 participants of a health examination at Chang Gung Memorial Hospital (CGMH), Taiwan, between 2005 and 2007.
Results: Estimated glomerular filtration rate (eGFR)-MDRDc obtained the highest estimate of GFR (mean 101.5 ± 19.2 ml/min/1.73 m 2 ), followed by eGFR-MDRD (mean 83.8 ± 15.8 ml/min/1.73 m 2 ) and eGFR-CG (mean 79.4 ± 29.1 ml/min/1.73 m 2 ). The prevalence of CKD stage 3-5 was 1.9%, 5.1%, and 25.5% according to MDRDc, MDRD and CG equations, respectively. With respect to CKD staging, the agreement between eGFR-MDRDc and eGFR-CG (weighted kappa, k = 0.22) and that between eGFR-MDRD and eGFR-CG (weighted k = 0.30) was poor. Both the original MDRDc and MDRD indicated that subjects with risk factors for CKD had significantly lower eGFR and higher odds ratios for stage 3-5 disease than those without. Paradoxically, the mean eGFR-CG (or odds ratios) was higher (or lower) in subjects with hyperuricemia, hypertension, obesity, or metabolic syndrome than those without these risk factors.
Conclusions: The use of the CG equation in the Taiwanese population is inappropriate for screening individuals with CKD, and the MDRDc equation seems to be better for Taiwanese population.