The authors reply

Seegmiller and Ebert1 comment on the potential for inaccuracy of the measured glomerular filtration rate (GFR), especially at low levels of kidney function, when a 240-minute sampling protocol is used. We are aware of the significant debate in this area. However, the focus of this aspect of our study2 was the biological variation of measured and estimated GFR, not the accuracy of the estimated GFR compared with the measured GFR. We do not believe that individual biological variation would be affected by the sampling protocol, provided that a consistent protocol is used within and between patients.
Source: Kidney International - Category: Urology & Nephrology Authors: Tags: Letter to the Editor Source Type: research