Browsing by Author "Perich, Carmen"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Analytical performance of 17 general chemistry analytes across countries and across manufacturers in the INPUtS project of EQA organizers in Italy, the Netherlands, Portugal, United Kingdom and SpainPublication . Weykamp, Cas; Secchiero, Sandra; Plebani, Mario; Thelen, Marc; Cobbaert, Christa; Thomas, Annette; Jassam, Nuthar; Barth, Julian H.; Perich, Carmen; Ricós, Carmen; Faria, Ana PaulaBACKGROUND: Optimum patient care in relation to laboratory medicine is achieved when results of laboratory tests are equivalent, irrespective of the analytical platform used or the country where the laboratory is located. Standardization and harmonization minimize differences and the success of efforts to achieve this can be monitored with international category 1 external quality assessment (EQA) programs. METHODS: An EQA project with commutable samples, targeted with reference measurement procedures (RMPs) was organized by EQA institutes in Italy, the Netherlands, Portugal, UK, and Spain. Results of 17 general chemistry analytes were evaluated across countries and across manufacturers according to performance specifications derived from biological variation (BV). RESULTS: For K, uric acid, glucose, cholesterol and high-density density (HDL) cholesterol, the minimum performance specification was met in all countries and by all manufacturers. For Na, Cl, and Ca, the minimum performance specifications were met by none of the countries and manufacturers. For enzymes, the situation was complicated, as standardization of results of enzymes toward RMPs was still not achieved in 20% of the laboratories and questionable in the remaining 80%. CONCLUSIONS: The overall performance of the measurement of 17 general chemistry analytes in European medical laboratories met the minimum performance specifications. In this general picture, there were no significant differences per country and no significant differences per manufacturer. There were major differences between the analytes. There were six analytes for which the minimum quality specifications were not met and manufacturers should improve their performance for these analytes. Standardization of results of enzymes requires ongoing efforts.
- A category 1 EQA scheme for comparison of laboratory performance and method performance: An international pilot study in the framework of the Calibration 2000 projectPublication . Jansen, Rob; Nuthar, Jassam; Thomas, Annette; Perich, Carmen; Fernandez-Calle, Pilar; Faria, Ana Paula; Correia, Helena; Barth, Julian; Weykamp, Cas; Cobbaert, Christa; Thelen, Marc; Ricós, CarmenINTRODUCTION: In the modern healthcare service, patients receive care in multiple hospitals and healthcare settings. Therefore, harmonization of results from different methods and instruments, both between and within laboratories, is of the utmost importance. The present pilot study aims to test the use of a Category 1 EQA scheme across four European countries by assessing the current level of equivalence of test results. METHOD: This work was led by the Dutch External Quality Assurance Scheme SKML and involved 28 laboratories from three regions in the UK, Spain and Portugal, and 120 laboratories from The Netherlands. A set of six commutable samples, targeted with reference methods, were circulated and 18 biochemistry analytes were tested. RESULTS AND CONCLUSIONS: The Total Error (TE) score, defined as the probability (%) that results are within the Total Error Acceptable (TEA) limits, for the eighteen analytes was calculated. Our data show that there is a need for further harmonization of laboratory data, in particular for electrolytes (calcium, chloride, magnesium, sodium), enzymes (ALT, amylase, AST, LDH), lipids (HDL-cholesterol), and for substrates (creatinine, total protein). Lack of performance consistency between instruments was seen for most analytes. The lack of harmonization is still present despite manufacturer claims of established traceability.
- Post-standardization of routine creatinine assays: are they suitable for clinical applicationsPublication . Jassam, Nuthar; Weykamp, Cas; Thomas, Annette; Secchiero, Sandra; Sciacovelli, Laura; Plebani, Mario; Thelen, Marc; Cobbaert, Christa; Perich, Carmen; Ricós, Carmen; Paula, Faria A.; Barth, Julian H.Introduction Reliable serum creatinine measurements are of vital importance for the correct classification of chronic kidney disease and early identification of kidney injury. The National Kidney Disease Education Programme working group and other groups have defined clinically acceptable analytical limits for creatinine methods. The aim of this study was to re-evaluate the performance of routine creatinine methods in the light of these defined limits so as to assess their suitability for clinical practice. Method In collaboration with the Dutch External Quality Assurance scheme, six frozen commutable samples, with a creatinine concentration ranging from 80 to 239 μmol/L and traceable to isotope dilution mass spectrometry, were circulated to 91 laboratories in four European countries for creatinine measurement and estimated glomerular filtration rate calculation. Two out of the six samples were spiked with glucose to give high and low final concentrations of glucose. Results Results from 89 laboratories were analysed for bias, imprecision (%CV) for each creatinine assay and total error for estimated glomerular filtration rate. The participating laboratories used analytical instruments from four manufacturers; Abbott, Beckman, Roche and Siemens. All enzymatic methods in this study complied with the National Kidney Disease Education Programme working group recommended limits of bias of 5% above a creatinine concentration of 100 μmol/L. They also did not show any evidence of interference from glucose. In addition, they also showed compliance with the clinically recommended %CV of ≤4% across the analytical range. In contrast, the Jaffe methods showed variable performance with regard to the interference of glucose and unsatisfactory bias and precision. Conclusion Jaffe-based creatinine methods still exhibit considerable analytical variability in terms of bias, imprecision and lack of specificity, and this variability brings into question their clinical utility. We believe that clinical laboratories and manufacturers should work together to phase out the use of relatively non-specific Jaffe methods and replace them with more specific methods that are enzyme based.