This Article  • Full text  • PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Contact me when this article is cited  Related Content  • Similar articles in JAMA  Topic Collections  • Renal Diseases  • Renal Diseases, Other  • Statistics and Research Methods  • Alert me on articles by topic

	Since this article does not have an abstract, we have provided the first 150 words of the full text and any section headings.

To the Editor: Using data from the National Health and Nutrition Examination Surveys (NHANES 1988-1994 and NHANES 1999-2004), Dr Coresh and colleagues¹ documented an increasing prevalence of chronic kidney disease (CKD) in the United States related in part to increasing prevalence of hypertension and diabetes. However, we have some concern about the absolute percentage of patients with stage 3 CKD, defined as estimated glomerular filtration rate (GFR) between 30 and 59 mL/min/1.73 m². In the NHANES 1999-2004 study, the prevalence of CKD stage 3 was high (7.69%), implying that 15.5 million US individuals have GFR below 60 mL/min/1.73 m². There are 3 reasons these figures could be overestimated, due to the use of the Modification of Diet in Renal Disease (MDRD) Study formula with a resultant systematic GFR underestimation.

First, as stated by the authors, the MDRD Study formula was developed based on 1628 participants in whom GFR . . . [Full Text of this Article]

Pierre Delanaye, MD
pierre_delanaye@yahoo.fr
Department of Nephrology

Etienne Cavalier, MD
Department of Clinical Chemistry

Jean Marie Krzesinski, MD, PhD
Department of Nephrology
University of Liège
CHU Sart Tilman
Liège, Belgium