Calculated GFR [GFRA, GFRB]

Department of Laboratory Medicine
University of Washington

Clinical assay interference and limitations

Calculated GFR [GFRA, GFRB]

Methodology: Calculation by MDRD equation

GFR is calculated by the MDRD study equation, which is reasonably accurate in non-hospitalized patients with chronic kidney disease, but tends to underestimate GFR in other populations. It is inaccurate in patients with rapidly changing renal function. See NEJM 2006 354:2473 (http://content.nejm.org/cgi/content/full/354/23/2473 ). GFR, corrected for body surface area, was estimated using age, sex, race, and creatinine, following the recommendations of the National Kidney Disease Education Program (NKDEP - see http://www.nkdep.nih.gov/ ). If age or sex was unavailable at calculation time, or if the patient is under 18 years of age, GFR can be calculated using NKDEP web site: http://nkdep.nih.gov/professionals/gfr_calculators/index.htm. Questions can be directed via email to nkdep@info.niddk.nih.gov.