Assessing glomerular filtration rate (GFR) in elderly Chinese patients with chronic kidney disease (CKD): A comparison of various predictive equations

The aim of this study was to evaluate the applicability of formulas based on serum creatinine (SC) levels in elderly Chinese patients with CKD. A total of 103 elderly CKD patients were investigated. The GFR was estimated with Cockcroft-Gault-equation, MDRD1-equation, abbreviated MDRD-equation, Jelliffe-1973-equation, Mawer-equation, Hull-equation, Jelliffe-1971-equation, SC-reciprocal-equation, Gate-equation and Bjornsson-equation. The accuracy of estimated GFR (eGFR) values was compared with the 99mTc-DTPA-GFR (standardized GFR=sGFR) in elderly CKD patients. Bland-Altman analysis demonstrated that Hull-equation, Cockcroft-Gault-equation and Bjornsson-equation were better than the other ones. However, the agreement limits of all the equations exceeded the prior acceptable tolerances defined as 60ml/min/(1.73m²). Linear regressions showed that the slopes of Jelliffe-1973-equation, Cockcroft-Gault-equation and Bjornsson-equation were closer to the identical line. The median of difference of MDRD1-equation, abbreviated MDRD-equation and Gate-equation were smaller. Accuracy of Jelliffe-1973-equation, Cockcroft-Gault-equation and Hull-equation were better than those of the other equations. But 30% accuracy of all the equations were less than 70%. When compared the bias as well as accuracy of eGFR with sGFR values in different stages of CKD, GFR estimated by MDRD1-equation, Hull-equation, Cockcroft-Gault-equation and Jelliffe-1973-equation showed good results. These results suggested that when SC was checked with enzymatic method, GFR-estimation equations may show great bias in elderly Chinese CKD patients. Further improved formulas are needed to evaluate renal function in elderly Chinese patients with CKD.