Assessment of glomerular filtration rate in elderly patients with chronic kidney disease

We sought to evaluate various glomerular filtration rate (GFR) estimating equations in elderly patients with chronic kidney disease (CKD). A total of 332 Chinese elderly patients with CKD who had undergone technetium-99m diethylenetriaminepentaacetic acid (Tc-99m-DTPA) renal dynamic imaging were enrolled. The MDRD equation, the re-expressed MDRD equation, the Chinese equation, the Ruijin equation, the previously Japanese equation, the new Japanese equation, the CKD-EPI equation, and the BIS1 equation were compared. The median of difference between estimated GFR and standard GFR ranged from -9.78 to 1.79 ml/min/1.73 m(2). The interquartile range of difference ranged from 12.38 to 20.87 ml/min/1.73 m(2). Accuracy with a deviation < 30 % ranged from 44.9 to 66.3 %. However, none of the equations had accuracy up to the 70 % level. Bland-Altman analysis demonstrated that the precision ranged from 50.5-87.6 ml/min/1.73 m(2). The slopes of regression line ranged from -0.26 to 0.55 and the intercepts ranged from -18.71 to 11.07. In both the overall performance and the performances in different stage of CKD, GFR estimated by the BIS1 equation performed better results. None of the GFR estimating equations are suitable for the specific Chinese population tested. At present, the BIS1 equation may be the optimal one for elderly Chinese CKD patients.