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Biomedical subjects

M M Kimberly

Publications and source records attributed to M M Kimberly.

4 recordsLinked to original sources
PubMed2000

A reference method laboratory network for cholesterol: a model for standardization and improvement of clinical laboratory measurements.

BACKGROUND: Accurate and precise measurement of blood cholesterol plays a central role in the National Cholesterol Education Program's strategy to reduce the morbidity and mortality attributable to coronary heart disease. Matrix effects hamper the ability of manufacturers to adequately calibrate and validate traceability to the National Reference System for Cholesterol (NRS/CHOL). CDC created the Cholesterol Reference Method Laboratory Network (CRMLN) to improve cholesterol measurement by assisting manufacturers of in vitro diagnostic products with validation of the traceability of their assays to the NRS/CHOL. METHODS: CRMLN laboratories established the CDC cholesterol reference method (modification of the Abell-Levy-Brodie-Kendall chemical method) and are standardized using CDC frozen serum reference materials. CRMLN laboratories use common quality-control materials and participate in monthly external performance evaluations conducted by CDC. The CRMLN performance criteria require member laboratories to agree with CDC within +/-1.0% and maintain a CV < or =2.0%. RESULTS: From 1995 to 200 the CRMLN laboratories met the accuracy criterion 97% of the time and the precision criterion 99% of the time. During this time period, the CRMLN maintained an average bias to CDC of 0.01% and an average collective CV of 0.33%. CONCLUSIONS: CDC established the CRMLN as the first international reference method laboratory network. The CRMLN assists manufacturers in the validation of the calibration of their diagnostic products so that clinical laboratories can measure blood cholesterol more reliably. The CRMLN can serve as a model for other clinical analytes where traceability to a hierarchy of methods is needed and matrix effects of the field methods with processed calibrators or reference materials are present.

Calibration↗
PubMed1999

Selection, validation, standardization, and performance of a designated comparison method for HDL-cholesterol for use in the cholesterol reference method laboratory network.

BACKGROUND: Accurate and precise HDL-cholesterol (HDL-C) measurements are essential for effective application of National Cholesterol Education Program treatment guidelines. The Cholesterol Reference Method Laboratory Network (CRMLN) assists manufacturers of in vitro diagnostic products to establish traceability to the accuracy base. CRMLN sought to implement a designated comparison method (DCM) that overcomes the impracticalities of the expensive and labor-intensive reference method for HDL-C. METHODS: CRMLN evaluated candidate DCMs and selected one that uses 50-kDa dextran sulfate with magnesium ions as the precipitation reagent followed by measurement of cholesterol by the CDC reference method. After validating the method, we transferred it to all CRMLN laboratories and successfully standardized it using CDC frozen serum reference materials. CRMLN laboratories participate in monthly performance evaluations. RESULTS: CRMLN laboratories were able to meet a precision goal, as indicated by SD, of </=0.03 mmol/L (1 mg/dL) 94.4% of the time. They were able to meet a bias goal of </=0.05 mmol/L (2 mg/dL) for HDL-C <1.09 mmol/L (42 mg/dL) 97.3% of the time and a goal of </=3% for HDL-C >/=1.09 mmol/L (42 mg/dL) 95.6% of the time. CRMLN is working to further improve its performance by implementing a bias criterion of 0.03 mmol/L (1 mg/dL) for all HDL-C concentrations. CONCLUSIONS: CRMLN selected, validated, standardized, and implemented a DCM for HDL-C that is accurate, robust, transferable, and practical. The DCM is being used to assist manufacturers in calibrating their products so that ultimately, clinical laboratories using the products will more accurately measure HDL-C.

Cholesterol, HDL↗
PubMed1997

Point: status of lipid and lipoprotein standardization.

Cholesterol and triglyceride standardization procedures have been used extensively and continuously since the 1950s. Definitive and Reference Methods, as well as primary and secondary standards, have been developed and maintained as the basis for evaluating the accuracy of results by various methods in many laboratories. But, although standardization efforts for apolipoprotein A-I and B measurements have been reported in detail in the scientific literature, much less has been reported in the area of total and lipoprotein cholesterol and triglyceride standardization efforts. Standardized cholesterol and triglyceride concentrations, determined in multiple large epidemiological and clinical studies, have been instrumental to the National Cholesterol Education Program panels that have assessed the lipoprotein values associated with risk of coronary disease, and have determined the cutpoints that are now used extensively by physicians to guide diagnosis and treatment of individual patients.

Apolipoproteins↗