The aim of our study was to examine the "real-world" characteristics of serum creatinine as a screening test for chronic kidney disease (CKD) in elderly patients. We demonstrated that a serum creatinine level of 1.7 mg/dL (150 µmol/L) had very poor sensitivity (12.6%) for the detection of CKD. Therefore, we recommend that estimated GFR, and not serum creatinine level, be used for the screening of CKD. While we used the C-G equation to calculate GFR in our study, we do not advocate its use over any other valid method to estimate GFR. The NKF endorses the use of both the C-G equation and the MDRD Study equation as acceptable alternatives to estimate the GFR.1 We selected the C-G equation because it has been extensively validated in a variety of populations, is simple to use, and can be readily applied at the bedside with a basic calculator.1,2 As Bernheim and colleagues point out, the MDRD Study equation appears to provide excellent estimates of GFR. However, it has been less extensively studied and requires the use of a scientific calculator or handheld computer for its application.1 Furthermore, a recent study by Beddhu and colleagues3 calls into question the validity of fundamental assumption of the MDRD Study equation. Ultimately, the question of which equation to use is less important than the concept that GFR, and not the serum creatinine level, is the measure of kidney function.
Swedko PJ, Clark HD, Akbari A. A Better Alternative for Estimating Renal Function—Reply. Arch Intern Med. 2003;163(18):2249. doi:10.1001/archinte.163.18.2248-a