CONTEXT: Measured plasma or serum creatinine concentration is a primary component of equations used to calculate estimated glomerular filtration rate (eGFR). In recent years, most assay manufacturers have adopted creatinine calibration procedures that are traceable to the National Institute of Standards and Technology's Standard Reference Material 967. OBJECTIVES: To examine the current performance of creatinine assays, to compare changes in assay performance since 2003, and to examine the reliability of laboratory eGFR calculations. DESIGN: Serum samples spiked with different concentrations of creatinine were analyzed by participating laboratories in the College of American Pathologists' LN24 survey. Participants' reported values were compared against values measured by liquid chromatography-isotope dilution mass spectrometry. Participants were asked to calculate the eGFR for certain samples, and results were compared with those obtained from the 4-parameter Modification of Diet in Renal Disease equation. RESULTS: Biases among current creatinine methods are in the range of -5% to 10%, compared with -7% to 34% seen in a 2003 study. This degree of bias in eGFR calculations is of clinical significance only for concentrations near the cut points used to stage chronic kidney disease. Approximately 20% of laboratories report eGFR values that exceed ±1 mL/min per 1.73 m(2) from the expected eGFR using the 4-parameter Modification of Diet in Renal Disease equation. CONCLUSIONS: Since 2003, there have been improvements in the performance of creatinine assays, which appear to be related to the adoption of standard reference materials for calibration. The effect of the observed method biases in clinical practice now appears minimal. Laboratories should continue to monitor the accuracy of eGFR calculations.
CONTEXT: Measured plasma or serum creatinine concentration is a primary component of equations used to calculate estimated glomerular filtration rate (eGFR). In recent years, most assay manufacturers have adopted creatinine calibration procedures that are traceable to the National Institute of Standards and Technology's Standard Reference Material 967. OBJECTIVES: To examine the current performance of creatinine assays, to compare changes in assay performance since 2003, and to examine the reliability of laboratory eGFR calculations. DESIGN: Serum samples spiked with different concentrations of creatinine were analyzed by participating laboratories in the College of American Pathologists' LN24 survey. Participants' reported values were compared against values measured by liquid chromatography-isotope dilution mass spectrometry. Participants were asked to calculate the eGFR for certain samples, and results were compared with those obtained from the 4-parameter Modification of Diet in Renal Disease equation. RESULTS: Biases among current creatinine methods are in the range of -5% to 10%, compared with -7% to 34% seen in a 2003 study. This degree of bias in eGFR calculations is of clinical significance only for concentrations near the cut points used to stage chronic kidney disease. Approximately 20% of laboratories report eGFR values that exceed ±1 mL/min per 1.73 m(2) from the expected eGFR using the 4-parameter Modification of Diet in Renal Disease equation. CONCLUSIONS: Since 2003, there have been improvements in the performance of creatinine assays, which appear to be related to the adoption of standard reference materials for calibration. The effect of the observed method biases in clinical practice now appears minimal. Laboratories should continue to monitor the accuracy of eGFR calculations.
Authors: Hedwig C M Stepman; Ulla Tiikkainen; Dietmar Stöckl; Hubert W Vesper; Selvin H Edwards; Harri Laitinen; Jonna Pelanti; Linda M Thienpont Journal: Clin Chem Date: 2014-03-31 Impact factor: 8.327
Authors: Christina M Parrinello; Morgan E Grams; David Couper; Christie M Ballantyne; Ron C Hoogeveen; John H Eckfeldt; Elizabeth Selvin; Josef Coresh Journal: Clin Chem Date: 2015-05-07 Impact factor: 8.327
Authors: Tiffany A Freed; Josef Coresh; Lesley A Inker; Douglas R Toal; Regis Perichon; Jingsha Chen; Kelli D Goodman; Qibo Zhang; Jessie K Conner; Deirdre M Hauser; Kate E T Vroom; Maria L Oyaski; Jacob E Wulff; Gudný Eiríksdóttir; Vilmundur Gudnason; Vicente E Torres; Lisa A Ford; Andrew S Levey Journal: Clin Chem Date: 2019-01-15 Impact factor: 8.327
Authors: Robert L Schmidt; Joely A Straseski; Kalani L Raphael; Austin H Adams; Christopher M Lehman Journal: PLoS One Date: 2015-11-24 Impact factor: 3.240