Can modifications of the MDRD formula improve the estimation of glomerular filtration rate in renal allograft recipients?
Background. Two modifications of the MDRD equation [the Mayo Clinic (MC) equation and Rule’s refitted (RR) MDRD formula] were proposed to overcome disadvantages of the original MDRD formula to calculate glomerular filtration rate (GFR). Additionally, a correction factor for the original MDRD formula has been introduced to adapt this formula to creatinine values measured by the isotope-dilution mass spectrometry (IDMS) method. Although precise determination of GFR is of central importance in renal transplant recipients, these equations have not been tested in these patients so far. Methods. Considering the impact of different creatinine calibrations, we analysed the MC equation and the RR-MDRD formula in comparison with the old as well as the re-expressed (IDMS traceable) MDRD equation and the Cockcroft–Gault (C–G) formula in 126 consecutive patients after kidney transplantation with respect to correlation, bias, precision, accuracy and ROC analysis. GFR was determined as technetium-die
