Author Affiliations: Harold Simmons Center for Kidney Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California (Dr Kalantar-Zadeh); Department of Medicine, David Geffen School of Medicine, and Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (Dr Kalantar-Zadeh); and Department of Medicine, University California-Irvine Medical Center, Orange, and School of Medicine, Irvine (Dr Amin).
The term chronic kidney disease (CKD) was first proposed and systematically defined in 2002, and the 5 incremental stages for the degree of severity of CKD were described based on the estimated glomerular filtration rate (GFR) (stage 1, ≥90; stage 2, 60-89; stage 3, 30-59; stage 4, 15-29; and stage 5, <15 mL/min/1.73 m2). Stage 1 is the least severe and stage 5 is classified as kidney failure.1,2 The estimated GFR (calculated from the Modification of Diet in Renal Disease [MDRD] Study equation)3 can be derived automatically from a single serum creatinine measurement, combined with the easily available age and sex data, plus a qualifying statement on race, and without a need for patient weight.
Kalantar-Zadeh K, Amin AN. Toward More Accurate Detection and Risk Stratification of Chronic Kidney Disease. JAMA. 2012;307(18):1976–1977. doi:10.1001/jama.2012.4623