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1.
Summary The precise and accurate laboratory measurement of blood cholesterol has become a national public health priority in the diagnosis and management of patients at risk for coronary heart disease. Unreliable measurements can hamper the national program to control heart disease. The National Cholesterol Education Program (NCEP) recommends that manufacturers and clinical laboratories achieve traceability to the National Reference System for Cholesterol in order to reliably classify patients according to the NCEP guidelines for assessing coronary heart disease risk. Documenting the accuracy of certain clinical analytical systems for the measurement of cholesterol has been complicated by the occurrence of fluid matrix effects. The major difficulty is that some processed materials (including calibrators, controls, proficiency survey samples, and reference materials) may not be reliable and may result in inaccurate measurement of patient specimens. Similarly, use of such material in accuracy assessment or proficiency testing may yield erroneous conclusions regarding system accuracy. Here, we will review the problem of matrix effects in cholesterol materials and present the results of several studies evaluating sources of matrix error. An alternate approach to documenting accuracy, to be used until commutable materials free of matrix effects are available, will also be discussed. 相似文献
2.
J. S. Morton S. A. Woolf T. I. McIntyre 《Journal of Radioanalytical and Nuclear Chemistry》2001,248(1):175-177
In 1999, the Department of Energy Office of Environmental Management (DOE-EM) National Analytical Management Program (NAMP) established a Radiological Traceability Program (RTP) as a new initiative for the radioanalytical acitivies related to the environmental programs conducted throughout the DOE complex. The National Analytical Management Program entered into an interagency agreement with the National Institute of Standards and Technology (NIST) to establish traceability to the national standard for DOE-EM radioanalytical activities through the NIST/reference laboratory concept as described in ANSI N42.23-1996.1 Using the criteria established by the RTP, NAMP named two DOE-EM laboratories as reference or secondary laboratories and established a program with NIST that demonstrated the concept of traceability. In order to gain and maintain traceability to NIST, each reference laboratory must meet the performance criteria as defined by the RTP and NAMP. Traceability to NIST is tiered down to each radioanalytical laboratory (monitor or service) that successfully participates in the performance-evaluation programs offered by the reference laboratories. Essential to the RTP is the demonstration that the reference laboratories can produce performance-testing (PT) materials of high quality as well as analyze/verify the radionuclide concentration to the required accuracy and precision. This paper presents the elements of the RTP and the program requirements of NIST and the reference laboratories. 相似文献
3.
Dave Armbruster 《Accreditation and quality assurance》2009,14(7):393-398
A goal of clinical laboratory science is to produce accurate and comparable patient test results for a specimen independent
of analytical methodology. The In Vitro Diagnostics Directive in Europe has provided the impetus for the U.S. in vitro diagnostic
(IVD) industry to adapt the concepts of Metrology, the science of measurement, including measurement traceability and measurement
uncertainty. The joint committee for traceability in laboratory medicine has provided a valuable database of internationally
recognized reference materials and methods and reference laboratories. Much of the responsibility for measurement traceability
falls on IVD manufacturers, but all global stakeholders, including the clinical laboratory profession, government Regulatory
bodies, metrology institutes, and the providers of EQA/PT surveys, must cooperate to progress toward this goal. The adaptation
of the concepts of Metrology to the clinical laboratory is an appropriate and logical development and it will continue in
the twenty-first century. 相似文献
4.
The Clinical Laboratory Improvement Amendments of 1988 (CLIA88) had a groundbreaking effect on laboratory professionals, instrument and reagent manufacturers, and regulators in the United States, and by association, worldwide. CLIA88 defined new levels of responsibility for all three of these stakeholders in modern laboratory testing. As a result, we envisioned a CLIA-driven approach to regulations, which in effect, created a three-member quality alliance. In 2003, the long awaited CLIA updates to the quality control and quality assurance requirements were published. The revisions in CLIA 2003 will herald an era in which manufactures take responsibility for meeting new standards of quality (improved accuracy and precision or reduced total allowable error) in the clinical laboratory and, especially, at point of care where testing is performed by non-laboratorians. The European (Bureau International des Poids ed Mesures) efforts at traceability, the National Committee of Clinical Laboratory Standards efforts at estimating total allowable error, and the new CLIA 2003 quality systems approach for quality requirements return to the fundamental concepts of accuracy to assess the efficacy of clinical laboratory testing.Presented at the 8th Conference on Quality in the Spotlight, 17–18 March 2003, Antwerp, Belgium 相似文献
5.
Thomas JB Duewer DL Mugenya IO Phinney KW Sander LC Sharpless KE Sniegoski LT Tai SS Welch MJ Yen JH 《Analytical and bioanalytical chemistry》2012,402(2):749-762
Standard Reference Material 968e Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum provides certified values
for total retinol, γ- and α-tocopherol, total lutein, total zeaxanthin, total β-cryptoxanthin, total β-carotene, 25-hydroxyvitamin
D3, and cholesterol. Reference and information values are also reported for nine additional compounds including total α-cryptoxanthin,
trans- and total lycopene, total α-carotene, trans-β-carotene, and coenzyme Q10. The certified values for the fat-soluble vitamins and carotenoids in SRM 968e were based on the agreement of results from
the means of two liquid chromatographic methods used at the National Institute of Standards and Technology (NIST) and from
the median of results of an interlaboratory comparison exercise among institutions that participate in the NIST Micronutrients
Measurement Quality Assurance Program. The assigned values for cholesterol and 25-hydroxyvitamin D3 in the SRM are the means of results obtained using the NIST reference method based upon gas chromatography-isotope dilution
mass spectrometry and liquid chromatography-isotope dilution tandem mass spectrometry, respectively. SRM 968e is currently
one of two available health-related NIST reference materials with concentration values assigned for selected fat-soluble vitamins,
carotenoids, and cholesterol in human serum matrix. This SRM is used extensively by laboratories worldwide primarily to validate
methods for determining these analytes in human serum and plasma and for assigning values to in-house control materials. The
value assignment of the analytes in this SRM will help support measurement accuracy and traceability for laboratories performing
health-related measurements in the clinical and nutritional communities. 相似文献
6.
G. Price 《Accreditation and quality assurance》1996,1(4):150-159
Economic and technological change, regional and international trade and the globalisation of industry have led to intense
pressures for improvements to analytical quality, reliability and comparability. Of central importance are national traceability
structures connecting chemical measurements in the field with internationally accepted measurement units and their practical
realisations. Australia has a developed physical and engineering measurement system, a legislative framework for analytical
traceability and, in the National Association of Testing Authorities, a recognised laboratory accreditation system. The need
has been identified to develop the technical capability to perform matrix-independent reference measurements for the certification
of traceable reference materials, useable as practical analytical etalons to establish metrological control systems in field
measurements for amounts of substance. Recently, a unique collaborative consortium has proposed a National Analytical Reference
Laboratory (NARL). The NARL is designed to be a metrological mass spectrometry facility for the transference of measurement
units to more widely useable chemical measurement standards and reference materials.
Received: 10 October 1995 Accepted: 26 October 1995 相似文献
7.
Historically, due to the size and nature of the instrumentation, highly skilled laboratory professionals performed clinical
testing in centralized laboratories. Today’s clinicians demand realtime test data at the point of care. This has led to a
new generation of compact, portable instruments permitting ”laboratory” testing to be performed at or near the patient’s bedside
by nonlaboratory workers who are unfamiliar with testing practices. Poorly controlled testing processes leading to poor quality
test results are an insidious problem facing point of care testing today. Manufacturers are addressing this issue through
instrument design. Providers of clinical test results, regardless of location, working with manufacturers and regulators must
create and manage complete test systems that eliminate or minimize sources of error. The National Committee for Clinical Laboratory
Standards (NCCLS) in its EP18 guideline, ”Quality management for unit-use testing,” has developed a quality management system
approach specifically for test devices used for point of care testing (POCT). Simply stated, EP18 utilizes a ”sources of error”
matrix to identify and address potential errors that can impact the test result. The key is the quality systems approach where
all stakeholders – professionals, manufacturers and regulators – collaboratively seek ways to manage errors and ensure quality. We illustrate the use of one quality systems approach, EP18, as a means to advance the quality of test results at point of
care.
Received: 26 June, 2002 Accepted: 17 July 2002
Presented at the European Conference on Quality in the Spotlight in Medical Laboratories, 7–9 October 2001, Antwerp, Belgium
Abbreviations NCCLS National Committee for Clinical Laboratory Standards (formerly) · POCT point of care testing · QC quality control ·
HACCP hazard analysis critical control points · CLIA clinical laboratory improvement amendments (of 1988)
Correspondence to S. S. Ehrmeyer 相似文献
8.
Mathias M. Müller 《Accreditation and quality assurance》2003,8(7-8):340-345
In laboratory medicine meaningful measurements are essential for diagnosis, risk assessment, treatment and monitoring of patients. Thus methods applied in diagnostic measurements must be accurate, precise, specific and comparable among laboratories. Inadequate or incorrect analytical performance has consequences for the patients, the clinicians, and the health care system. One key element of metrology is the traceability of a measurement result to the SI system ensuring comparable results. This principle is described in the ISO/TC 212/WG2 N65 prEN 17511 Standard. In addition to the principles of metrology, the clinical usefulness, the diagnostic needs, and the biological and disease associated variations in patients' specimens have to be considered when the analytical biases for diagnostic purposes are defined. It must be the general goal of diagnostic laboratories to produce results that are true and comparable worldwide. The recent European in vitro diagnostic (IVD) Directive 98/79 EC follows the above mentioned standard of the International Organization for Standardization (ISO) and the European Committee for Standardization (CEN) requesting its application for all IVD reagents used within the European Union. This new European legislation will have a worldwide impact on manufacturers and clinical laboratories and will be implemented in 2003. It states that "traceability of values assigned to calibrators and/or control materials must be assured through available reference measurement procedures and/or available reference materials of a higher order". Thus a worldwide reference system needs to be established by collaboration and mutual recognition between the United States National Institute of Standards and Technology (NIST), European Metrology Institutes (EUROMET), regulatory bodies (e.g. United States Food and Drug Administration, FDA) the IVD industry and professional organizations (e.g. International Federation of Clinical Chemistry and Laboratory Medicine, IFCC). In June 2002, in Paris, representatives of international and regional organizations and institutions decided to form the "Joint Committee on Traceability for Laboratory Medicine" (JCTLM), which will support industry in registration and licensing of the "CE" label to test systems conforming to the IVD Directive.Presented at the International ILAC/IAF Conference on Accreditation in Global Trade, 23–25 September 2002, Berlin, Germany 相似文献
9.
Purity certified reference materials (CRMs) are playing a key role in metrological traceability, because they form the basis
for many traceability chains in chemistry. Recently, the National Metrology Institute of Japan (NMIJ) has developed two purity
CRMs for creatinine (NMIJ CRM 6005-a) and urea (NMIJ CRM 6006-a), because the concentrations of these two compounds are frequently
measured in clinical laboratories for monitoring the renal functions. In the certification of purity CRMs, it is essential
that the materials have been thoroughly characterized for purity, and the purity should preferably be determined directly
by a primary method of measurements. In the development of these two CRMs, we used the purified materials as candidates. The
certified values were assigned based on the results of two different methods; acidimetric titration and nitrogen determination
by the Kjeldahl method. Since both methods cannot distinguish some impurities from the target compounds, major impurities
in the candidate materials were also identified, quantified, and subtracted. These CRMs can provide a traceability link between
routine clinical methods and SI units.
Presented at BERM-11, October 2007, Tsukuba, Japan. 相似文献
10.
R. Dybkaer 《Accreditation and quality assurance》2001,6(1):16-19
The medical laboratory must provide results of measurements that are comparable over space and time in order to aid medical
diagnosis and therapy. Thus, metrological traceability, preferably to the SI, is necessary. The task is formidable due to
the many disciplines involved, the high production rate, short request-to-report time, small sample volumes, microheterogeneity
of many analytes, and complex matrices. The prerequisite reference measurement systems include definition of measurand, unit
of measurement (when applicable), consecutive levels of measurement procedures and calibrators in a calibration hierarchy,
international organizations, reference measurement laboratories, dedicated manufacturers, written standards and guides for
the medical laboratory, production of reference materials, internal and external quality control schemes, and increasingly
accreditation. The present availability of reference measurement procedures and primary calibrators is shown to be insufficient
to obtain international comparability of all types of quantity in laboratory medicine.
Received: 19 April 2000 / Accepted: 3 July 2000 相似文献
11.
Fred D. Lasky 《Accreditation and quality assurance》2001,6(9-10):415-420
In vitro diagnostic (IVD) manufacturers play an important role in helping to provide laboratory results that meet the needs of patient care. Industry, the primary source of new technologies, uses established processes to assure a continuous supply of products that satisfies health care needs. The processes include validation of user needs, with well-controlled procedures that are used to manufacture quality products. Management uses routine audits and customer complaint monitoring to identify improvement opportunities. The processes used in the IVD industry are recognized quality practices that should be, and often are, used in the clinical laboratory. 相似文献
12.
Satterfield MB Sniegoski LT Sharpless KE Welch MJ Hornikova A Zhang NF Pfeiffer CM Fazili Z Zhang M Nelson BC 《Analytical and bioanalytical chemistry》2006,385(3):612-622
Total homocysteine (tHCY) and folate are interrelated biomarkers for arteriosclerosis and coronary heart disease. Although many different methods for both tHCY and folate are clinically available, the intermethod and interlaboratory results are often poor, resulting in the need for a matrix reference material and reference methods. The National Institute of Standards and Technology (NIST) has developed isotope dilution liquid chromatography/mass spectrometry (LC/MS) and liquid chromatography/ tandem mass spectrometry (LC/MS/MS) methods for determination of tHCY and several folate forms including 5-methyltetrahydrofolic acid (5MT) and folic acid (FA). Additionally, a method for simultaneous measurement of tHCY, 5MT, and FA has been developed and validated. In collaboration with the Centers for Disease Control and Prevention (CDC), mass spectrometric methods and methods used in clinical laboratories have been applied to characterize a new Standard Reference Material (SRM), SRM 1955, "Homocysteine and Folate in Human Serum," containing low, medium, and high levels of tHCY and 5MT. Additionally, FA, 5-formyltetrahydrofolic acid (5FT), vitamin B12, and total folate values are provided. Use of the new SRM should improve clinical measurements and will permit traceability to internationally recognized certified reference materials, as described by European Directive 98/79/EC on in vitro diagnostic medical devices. 相似文献
13.
Sharpless KE Greenberg RR Schantz MM Welch MJ Wise SA Ihnat M 《Analytical and bioanalytical chemistry》2004,378(5):1161-1167
Well-characterized reference materials are needed by laboratories in the food testing and nutrition communities to facilitate compliance with nutritional labeling laws, to provide traceability for food exports needed for acceptance in many foreign markets, and to improve the accuracy of nutrition information that is provided to assist consumers in making sound dietary choices. As a result of the enactment of the Nutrition Labeling and Education Act of 1990 and the Infant Formula Act of 1980, the National Institute of Standards and Technology (NIST) has developed a suite of food-matrix Standard Reference Materials (SRMs) characterized for nutrient concentrations. These include SRM 1544 Fatty Acids and Cholesterol in a Frozen Diet Composite, SRM 1546 Meat Homogenate, SRM 1548a Typical Diet, SRM 1566b Oyster Tissue, SRM 1846 Infant Formula, SRM 1946 Lake Superior Fish Tissue, SRM 2383 Baby Food Composite, SRM 2384 Baking Chocolate, SRM 2385 Spinach, and SRM 2387 Peanut Butter. Many of these materials were developed at the request of the food industry to populate a nine-sectored fat-protein-carbohydrate triangle developed by AOAC International. With the completion of SRM 2387, SRMs representing each sector of the triangle are now available. These food-matrix reference materials are intended primarily for validation of analytical methods for the measurement of proximates, fatty acids, vitamins, minerals, and so on in foods of similar composition. They may also be used as "primary control materials" in the value-assignment of in-house, secondary, control materials to confirm accuracy as well as to establish traceability to NIST. 相似文献
14.
Qing Huang Hanyu Qian Dong Feng Yao Wang Nan Luo Suya Lu Qingshui Shi Mei Zhang Yihong Lu Li Tan 《Journal of separation science》2020,43(11):2042-2052
The current quality control methods relying mainly on chromogenic reaction can hardly ensure the quality and safety of the biochemical drug with complex chemical composition. Therefore, a chromatographic fingerprint method was developed for the quality evaluation of a multicomponent biochemical drug, transfer factor injection. High‐performance liquid chromatography fingerprint was measured by using a C18 column (250 × 4.6 mm, 5 µm) with a mobile phase composed of 0.1% trifluoroacetic acid–water and 0.085% trifluoroacetic acid–acetonitrile under gradient elution. The developed method was validated and was subsequently applied to 57 batches of commercial products which were sampled by National Drug Assessment Program. High‐resolution mass spectrometry analysis was performed on characteristic peaks of fingerprints, and a series of amino acids, nucleosides, and deoxynucleosides were identified. In the fingerprint assessments, principal component analysis and Hotelling T2 analysis yielded the best results. The results generally indicated that there was a significant difference among products of batch‐to‐batch or from different manufacturers. Abnormal samples and its discriminatory components were also explored. In summary, the established fingerprinting method with multivariate statistical analysis could offer an efficient, reliable, and practical approach for quality consistency evaluation of transfer factor injection, providing a reference for the quality control of other multicomponent biochemical drugs. 相似文献
15.
The NOAA National Status and Trends (NS&T) Program determines the current status of, and changes over time in the environmental health of U.S estuarine and coastal waters. Concentrations of organic and inorganic contaminants are determined in bivalves, bottom-dwelling fish and sediments. The quality of the analytical data generated by the NS&T Program is over-seen by the performance-based Quality Assurance Project, which is designed to document sampling protocols, analytical procedures, and laboratory performance, and to reduce intralaboratory and interlaboratory variation. All NS&T cooperating laboratories are required to participate in yearly intercomparison exercises. The analysis of reference materials, such as the National Research Council of Canada's Certified Reference Materials (CRMs) and National Institute of Standards and Technology's (NIST) Standard Reference Materials (SRMs), and of control materials, is required. Because of the need for marine matrix reference materials and standards, NOAA contributed to the production of eight NIST SRMs and seven internal standard solutions. Analytical data from all control materials and all matrix reference materials are reported to the Program office. 相似文献
16.
G. Price 《Accreditation and quality assurance》1996,1(2):57-66
National measurement systems are infrastructures to ensure, for each nation, a consistent and internationally recognised
basis for measurement. Such complex systems have historical, technical, legal, organisational and institutional aspects to
connect scientific metrology with practical measurements. Underlying any valid measurement is a chain of comparisons linking
the measurement to an accepted standard. The ways the links are forged and the etalons (measurement standards) to which they
connect are defining characteristics of all measurement systems. This is often referred to as traceability which aims at basing
measurements in common measurement units – a key issue for the integration of quantitative chemical analysis with the evolving
physical and engineering measurement systems. Adequate traceability and metrological control make possible new technical capabilities
and new levels of quality assurance and confidence by users in the accuracy and integrity of quantitative analytical results.
Traceability for chemical measurements is difficult to achieve and harder to demonstrate. The supply of appropriate etalons
is critical to the development of metrology systems for chemical analysis. An approach is suggested that involves the development
of networks of specialised reference laboratories able to make matrix-independent reference measurements on submitted samples,
which may then be used as reference materials by an originating laboratory using its practical measurement procedures.
Received: 31 July 1995 Accepted: 19 August 1995 相似文献
17.
S. Duta Y. Aregbe L. Van Nevel P. Taylor F. Iacobescu 《Accreditation and quality assurance》2006,10(10):554-561
On the basis of quantitative chemical measurements many important decisions are made in support of legislation or in industrial processes or social aspects. For this reason it is important to improve the quality of chemical measurement results and thus make them comparable and acceptable everywhere. The measurement quality is important to enable an equivalent implementation of the European Union regulations and directives across an enlarged EU. In this context, the European Commission–Joint Research Centre–Institute for Reference Materials and Measurement (EC-JRC-IRMM) set up a programme to improve the scientific basis for metrology in chemistry (MiC) in EU candidate countries in the framework of EU enlargement. Several activities were initiated, such as training, fellowships, sponsoring of seminars, conferences and participation in interlaboratory comparisons. To disseminate measurement traceability, IRMM provides through its International Measurement Evaluation Programme (IMEP) an interlaboratory tool to enable the benchmarking of laboratory performance. IMEP emphasizes the metrological aspects of measurement results, such as traceability and measurement uncertainty. In this way it has become a publicly available European tool for MiC. The Romanian Bureau of Legal Metrology – National Institute of Metrology (BRML-INM) actively supports the participation of Romanian authorized and field laboratories in IMEP interlaboratory comparisons. This paper describes the interest of Romanian laboratories participating in this programme, the analytical and metrological problems that became relevant during these exercises and some actions for improvement. The results from Romanian laboratories participating in IMEP-12 (water), IMEP-16 (wine), IMEP-17 (human serum) and IMEP-20 (tuna fish) are presented. To conclude, the educational and training activities at national level organized jointly by the Romanian National Institute of Metrology (INM) and IRMM are also mentioned. 相似文献
18.
The European Commission (EC) Directive on in vitro diagnostic medical devices requires—amongst other obligations—manufacturers to establish metrological traceability of values assigned to calibrators to available measurement procedures and/or available reference materials of a higher order. Manufacturers use different procedures to accomplish this task and to indicate uncertainties of assigned values. Medical laboratories may want to calculate the uncertainties of their results or accreditation bodies may require them to do so. For this purpose some practical approaches are presented and some examples discussed.Presented at the Roche Diagnostic Workshop on In Vitro Diagnostics Directive: A Nordic event about the implication of traceability and uncertainty in practice, 13–15 February, 2003, Helsinki, Finland. Organized in connection with Labquality Days, 13 February, 2003, Helsinki. 相似文献
19.
R. Dybkaer Ulf Örnemark Adam Uldall Wolfgang Richter 《Accreditation and quality assurance》1999,4(8):349-351
In a recent Letter to the Editor, Dr. B. Neidhart questioned the need to make clinical chemical measurement results traceable to international standards and
to incorporate the principles of analytical quality assurance into clinical chemistry. An analysis of the arguments presented
shows that modern laboratory medicine has to deliver accurate results, which are comparable over space and time, in order
to improve the accuracy of diagnostic tools and minimize cost. The means to achieve accuracy and comparability are metrological
traceability and quality assurance as supported by many national and international initiatives. 相似文献
20.
Mary M. Kimberly 《Accreditation and quality assurance》2004,9(4-5):239-241
In 1968, clinical chemistry was considered to be the field most in need of certified reference materials (CRMs). While significant progress has been made in this area, new diagnostic assays are continually being developed that create a need for new CRMs. Members of the clinical laboratory community help to identify reference material needs. Professional and governmental organizations, such as IFCC, AACC, NCCLS, CDC, and the national metrological institutes (NMIs), respond to develop protocols and materials. Several measurands are presented as examples. In the late 1950s and early 1960s, in response to a need for standardization of lipid and lipoprotein measurements, CDC developed a reference system that included secondary reference materials. Over the years, the process of preparation of these materials was refined, eventually leading to the development of NCCLS guideline for preparation of commutable frozen serum pools for use as secondary reference materials (C37-A). This protocol was used for the preparation of NIST SRM 1951a (lipids in frozen (liquid) human serum). In the 1980s, a need for a reference material for blood lead was identified. CDC and NIST cooperated to develop SRM 955 (lead in bovine blood). More recently, efforts have been initiated to standardize high-sensitivity C-reactive protein (hsCRP) assays. In this case, a CRM for CRP existed (CRM 470, developed by IFCC and available from IRMM), but at concentrations in the acute phase reactant range and not in the low range needed for hsCRP assays. CDC coordinated a study to evaluate diluted CRM470 and other candidate materials as secondary reference materials for hsCRP assays.Presented at BERM-9—Ninth International Symposium on Biological and Environmental Reference Materials, June 15–19, 2003, Berlin, Germany. 相似文献