BACKGROUND: Variation among clinical laboratories in calibration of serum @entity1011 assays is a source of error in glomerular filtration rate (GFR) estimation equations. We evaluated impact of this variation on GFR estimates. METHODS: Errors in GFR estimates were computed based on the range of calibration differences from the 1994 College of American Pathologists (CAP) survey using the @entity8 ( @entity8 ) Study GFR equation. RESULTS: Mean (95% CI) calibration difference observed in the CAP survey was +0.14 mg/dL (+12.4 micromol/L) [-0.09, +0.37 mg/dL (-7.96, +32.71 micromol/L)]. Errors in GFR estimates using uncalibrated serum @entity1011 values were lower in individuals with lower estimated GFR. For GFR of 60 mL/min/1.73 m(2), the mean calibration difference in the CAP survey was associated with errors in GFR estimation between -5.5 to -8.1 mL/min/1.73 m(2) (-9.1 to -13.5%) depending on race and sex. The 95% confidence interval for the calibration difference was associated with a maximal range of error in GFR estimates from +4.6 to -18.1 mL/min/1.73 m(2) (+7.6 to -30.2%). Errors of this magnitude at an estimated GFR of 60 mL/min/1.73 m(2) are not likely to be of clinical significance. However, errors at higher levels of estimated GFR would be greater, making GFR estimates in this range unreliable. CONCLUSION: Recalibration of serum @entity1011 assays to the @entity8 Study clinical laboratory would improve accuracy of GFR estimation using the @entity8 Study equation, but is not practical for all clinical laboratories. As an interim solution, clinical laboratories could report GFR estimates <60 mL/min/1.73 m(2) without recalibration with an acceptable accuracy.

Variation in the serum XXXX assay calibration: a practical application to glomerular filtration rate estimation.

@entity1011 :: ('MESH:D003404', 'Chemical') :: ['creatinine'] @entity8 :: ('MESH:D007674', 'Disease') :: ['MDRD', 'Modification of Diet in Renal Disease']
@entity1011 :: (MESH:D003404,Chemical) :: ['creatinine']
