alexa Standardization of serum creatinine and estimated GFR in the Kidney Early Evaluation Program (KEEP).
Toxicology

Toxicology

Journal of Drug Metabolism & Toxicology

Author(s): Stevens LA, Stoycheff N

Abstract Share this page

Abstract BACKGROUND: Creatinine calibration by clinical laboratories is important because variability among assays adversely affects the accuracy of glomerular filtration rate (GFR) estimation. We describe the calibration of creatinine assays used in the National Kidney Foundation Kidney Early Evaluation Program (KEEP). METHODS: Creatinine values were requested for 200 samples at each of the 2 KEEP laboratories, Satellite Laboratory Services, LLC (2000 to 2005) and Clinical Laboratory Services (CLS; 2005 to present), for comparison with samples at the Cleveland Clinic Research Laboratory (CCRL). Linear regression and Deming regression were used to obtain slopes adjusted for measurement error and regression to the mean. RESULTS: After exclusion of outliers, mean creatinine level in 184 samples was 0.94 mg/dL at Satellite compared with 0.89 mg/dL at CCRL. Deming regression showed a slope of 1.003 (95\% confidence interval (CI), 0.99 to 1.02; P < 0.001) and intercept of -0.04 (95\% CI, -0.59 to -0.02; P = 0.003) with R(2) = 0.9853. Final calibration consists of intercept alone because of a small slope. After exclusion of outliers, mean creatinine level in 199 samples was 1.06 mg/dL at CLS compared with 0.96 mg/dL at CCRL. Deming regression showed a slope of 1.08 (95\% CI, 1.07 to 1.09; P < 0.001) and intercept of -0.18 (95\% CI, -0.19 to -0.17; P < 0.001) with R(2) = 0.9939. GFR estimates were minimally affected by the Satellite calibration. At a serum creatinine value of 1 mg/dL, the change in estimated GFR was 1 mL/min/1.73 m(2) after calibration. Conversely, higher range GFR estimates were affected by calibration of the CLS creatinine assay. At a serum creatinine value of 1 mg/dL, the GFR estimate was 6 mL/min/1.73 m(2) higher after calibration. CONCLUSION: Calibration of KEEP creatinine measurements had a greater impact on the current laboratory than on the laboratory previously used. The calibration process has worked to decrease overestimation of eGFR at the high range and decrease misclassification bias. This article was published in Am J Kidney Dis and referenced in Journal of Drug Metabolism & Toxicology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords