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

Purpose: We sought to evaluate various glomerular filtration rate (GFR) estimating equations in elderly patients with chronic kidney disease (CKD).

Methods: A total of 332 Chinese elderly patients with CKD who had undergone technetium-99m diethylenetriaminepentaacetic acid ((99m)Tc-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.

Results: 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.

Conclusion: 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.