Nijmegen, Netherlands
Nijmegen, Netherlands
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Cobbaert C.,Leiden University | Weykamp C.,Beatrix Hospital | Franck P.,Haga Hospital | de Jonge R.,EMCR | And 5 more authors.
Clinica Chimica Acta | Year: 2012

Background: Equivalence of results among laboratories is a major mission for medical laboratories. Monitoring of test equivalence is structurally integrated in the Dutch External Quality Assessment (EQA) scheme since 2005. Commutable poolsera, single donation "spy" sera and biological variance tolerance limits have been introduced in the EQA scheme for evaluation of the degree of test equivalence and its determinants. Methods: In the annual cycle scheme 24 samples, covering the (patho)physiological measuring range for 17 analytes, are assayed by 220 participating laboratories at biweekly intervals. Test equivalence was evaluated by calculating overall median interlaboratory coefficients of variation (CVs) and its bias and imprecision components. Data from 2005 and 2010 schemes are evaluated to investigate trends in performance and success of standardization efforts. Results: Overall median interlaboratory CVs in 2010 were mostly better than in 2005. Median interlaboratory CVs became <. 5% for electrolytes and substrates, and <. 10% for enzymes. Improvement in median interlaboratory CVs over these five years is mainly explained by improved method standardization, especially for enzymes and creatinine. Conclusion: The Dutch EQA-program proves to be a powerful instrument to evaluate test equivalence. It allows monitoring standardization efforts in a highly effective way and gives insight into remaining standardization potential. © 2012 Elsevier B.V.

McMurray J.,Association for Clinical Biochemistry | Zerah S.,Laboratoire ZTP | Hallworth M.,Royal Shrewsbury Hospital | Schuff-Werner P.,University of Rostock | And 26 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2010

In 1997, the European Communities Confederation of Clinical Chemistry and Laboratory Medicine (EC4) set up a Register for European Specialists in Clinical Chemistry and Laboratory Medicine. The operation of the Register is undertaken by a Register Commission (EC4RC). During the last 12 years, more than 2200 specialists in Clinical Chemistry and Laboratory Medicine have joined the Register. In 2007, EC4 merged with the Forum of European Societies of Clinical Chemistry and Laboratory Medicine (FESCC) to form the European Federation of Clinical Chemistry and Laboratory Medicine (EFCC). Two previous Guides to the Register have been published, one in 1997 and another in 2003. The third version of the Guide is presented in this article and is based on the experience gained and development of the profession since the last revision. Registration is valid for 5 years and the procedure and criteria for re-registration are presented as an Appendix at the end of the article. © 2010 by Walter de Gruyter, Berlin, New York.

Wieringa G.,Foundation Medicine | Zerah S.,Laboratoire Zerah Taar Pfeffer | Jansen R.,SKML | Simundic A.-M.,University of Zagreb | And 26 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2012

Laboratory medicine's practitioners across the European community include medical, scientific and pharmacy trained specialists whose contributions to health and healthcare is in the application of diagnostic tests for screening and early detection of disease, differential diagnosis, monitoring, management and treatment of patients, and their prognostic assessment. In submitting a revised common syllabus for post-graduate education and training across the 27 member states an expectation is set for harmonised, high quality, safe practice. In this regard an extended 'Core knowledge, skills and competencies' division embracing all laboratory medicine disciplines is described. For the first time the syllabus identifies the competencies required to meet clinical leadership demands for defining, directing and assuring the efficiency and effectiveness of laboratory services as well as expectations in translating knowledge and skills into ability to practice. In a 'Specialist knowledge' division, the expectations from the individual disciplines of Clinical Chemistry/Immunology, Haematology/Blood Transfusion, Microbiology/Virology, Genetics and In Vitro Fertilisation are described. Beyond providing a common platform of knowledge, skills and competency, the syllabus supports the aims of the European Commission in providing safeguards to increasing professional mobility across European borders at a time when demand for highly qualified professionals is increasing and the labour force is declining. It continues to act as a guide for the formulation of national programmes supplemented by the needs of individual country priorities. © 2012 by Walter de Gruyter • Berlin • Boston.

Delanghe J.R.,Ghent University | Cobbaert C.,LUMC | Harmoinen A.,Savonlinnan Aluelaboratorio | Jansen R.,SKML | And 2 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2011

The recent campaign for standardization of creatinine measurements has been promoted to allow the widespread use of formulas for estimating the glomerular filtration rate (GFR). However, studies on trueness verification and measurement interferences still show disappointing interassay variation of serum creatinine results. Creatinine recalibration has major clinical consequences. In particular, in pediatrics where reference ranges for serum and plasma creatinine are low, calculation of the GFR is problematic when based on alkaline picrate methods because of method non-specificity and the lack of appropriate GFR estimating formulas. Therefore, enzymatic creatinine assays are preferred. In the near future, cystatin C might offer an interesting alternative for GFR estimation. For the calculation of drug doses, the Modification of Diet in Renal Disease study formula generally offers reliable data. However, attention has to be paid to the elderly. Also, the calculation of the Model for End-Stage Liver Disease score, which is used to prioritize patients for liver transplantation, may significantly be influenced by recalibration of creatinine assays. Creatinine restandardization may also affect the current guidelines for referral of chronic kidney disease patients to nephrologists. © 2011 by Walter de Gruyter Berlin Boston.

Bais R., | Armbruster D.,Abbott Laboratories | Jansen R.T.P.,SKML | Klee G.,Mayo Medical School | And 3 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2013

Although manufacturers are compelled by the European IVD Directive, 98/79/EC, to have traceability of the values assigned to their calibrators if suitable higher order reference materials and/or procedures are available, there is still no equivalence of results for many measurands determined in clinical laboratories. The adoption of assays with metrological traceable results will have a significant impact on laboratory medicine in that results will be equivalent across different laboratories and different analytical platforms. The IFCC WG on Allowable Errors for Traceable Results has been formed to define acceptable limits for metrological traceability chains for specific measurands in order to promote the equivalence of patient results. These limits are being developed based on biological variation for the specific measurands. Preliminary investigations have shown that for some measurands, it is possible for manufacturers to assign values to assay calibrators with a measurement uncertainty that allows the laboratory enough combined uncertainty for their routine measurements. However, for other measurands, e.g., plasma sodium, current assays are too imprecise to fulfil limits based on biological variation. Although an alternative approach based on probability theory is being investigated, the most desirable approach would be for industry to improve measurement methods so that they meet clinical requirements.

Weykamp C.,Beatrixpark | Franck P.,Reference Laboratory for Enzymes | Gunnewiek J.K.,Gelderse Vallei Hospital | De Jonge R.,Rotterdam University | And 4 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2014

Conclusions: The EQA-initiated national harmonisation of seven enzymes, using stable, commutable human serum samples, spiked with human recombinant enzymes, and targeted with the IFCC Reference Measurement Procedures, was successful in terms of implementation of IFCC traceable results (95%), recovery of the target (99%), and inter-laboratory CV (4%).Results: Of the 223 participating laboratories, 95% reported IFCC traceable results, ranging from 98% (ASAT) to 87% (amylase). Users of Roche and Siemens (97%) more frequently reported in IFCC traceable results than users of Abbott (91%), Beckman (90%), and Olympus (87%). The success of harmonisation, expressed as the recovery of assigned values and the inter-laboratory CV was: ALAT (recovery 100%; inter-lab CV 4%), ASAT (102%; 4%), LD (98%; 3%), CK (101%; 5%), GGT (98%; 4%), AP (96%; 6%), amylase (99%; 4%). There were no significant differences between the manufacturers. Commutability was demonstrated in the parallel study. Equal results in the same sample in the 2012 and 2013 EQA programmes demonstrated stability of the samples.Background: Equivalent results between different laboratories enable optimal patient care and can be achieved with harmonisation. We report on EQA-initiated national harmonisation of seven enzymes using commutable samples.Methods: EQA samples were prepared from human serum spiked with human recombinant enzymes. Target values were assigned with the IFCC Reference Measurement Procedures. The same samples were included at four occasions in the EQA programmes of 2012 and 2013. Laboratories were encouraged to report IFCC traceable results. A parallel study was done to confirm commutability of the samples.

Cooper G.,W. Gregory Cooper LLC | DeJonge N.,Haga Teaching Hospital | Ehrmeyer S.,University of Wisconsin - Madison | Yundt-Pacheco J.,Bio Rad Laboratories Inc. | And 3 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2011

As a part of a series of yearly meeting, in May 2010 over 40 medical laboratory opinion leaders, pathologists, clinical biochemists and physicians from Europe, Israel and South Africa gathered together in Bardolino, Italy to discuss issues and current challenges for laboratory medicine, including a) the use of biological variation 10 years after the Stockholm Conference; b) achieving quality in point-of-care testing; c) assessing risk and controlling sources of error in the laboratory; d) determining the appropriate frequency of quality control; and f) putting laboratory medicine at the core of patient care. The intended goal of the convocation was to give laboratory professionals from different countries and backgrounds the opportunity to share ideas, concerns and experiences in previously mentioned areas of interest. This paper provide a synopsis of the reports from each working group. © 2011 by Walter de Gruyter Berlin New York.

Jansen R.T.P.,SKML | Slingerland R.J.,Isala Klinieken
Clinical Chemistry and Laboratory Medicine | Year: 2010

Background: Point-of-care glucose meters are used increasingly in semi- and non-professional context. The quality of glucose measurements depends on the quality of the equipment, the quality of use, and the pre-analytical conditions. In this article, a External Quality Assessment Scheme (SKML)-Quality Mark for point-of-care test (POCT) and self-test glucose meters is proposed, assessing analytical quality and technical quality. The analytical requirements are based on the biological variation concept, and a system to assess meters for the SKML-Quality Mark is described. Using the proposed system as an example, 14 meters were tested. Methods: The analytical quality of the POCT and self-test equipment was assessed for plasma calibrated glucose values by comparison with a trueness verified method traceable to the IFCC reference method in an accredited clinical laboratory. The concept is based on the biological variation system. The SKML-Quality Mark comprises the following criteria for blood glucose equipment: 1) Fulfilment of compliance with ISO 15197 and/or TNO guideline criterion; 2) Fulfilment of the total allowable error (TAE) criterion; 3) Fulfilment of the total allowable linearity bias criterion; 4) Fulfilment of the total allowable interfering substances bias criterion; and 5) Fulfilment of the haematocrit criterion. Results: The proposed SKML-Quality Mark system was tested on 14 commercial home-use meters. The TAE criterion is violated by two meters. The main reason for the violation is bias. For the majority of meters, the Passing and Bablok regression confidence interval does not include the intercept of 0.0 and slope of 1.0. In addition, Syx indicates dispersion around the line or non-linearity. The bias and total error at three different concentrations were investigated as part of the quality mark, resulting in disapproval of the Dicomed Sensocard Plus meter. The bias was significant for the Wellion Linus. With respect to interfering substances, bias of the same magnitude and sign as the bias without additive was seen for all meters for acetaminophen, indicating no additional interference. For ascorbic acid, an additional bias was seen for several meters. However, significant bias was demonstrated for the Sensocard Plus and Glucocard X-meter. Conclusions: The biological variation concept offers a scientific basis for assessment of acceptable deviation. The concept is extended in the SKML-Quality Mark correcting for the limited number of measurements that can be performed while assessing home-use or POCT meters. The results show that three out of 14 meters fail the proposed quality mark. © 2010 by Walter de Gruyter, Berlin, New York.

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