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.
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.
Authors: Hedwig C M Stepman; Ulla Tiikkainen; Dietmar Stöckl; Hubert W Vesper; Selvin H Edwards; Harri Laitinen; Jonna Pelanti; Linda M Thienpont Journal: Clin Chem Date: 2014-03-31 Impact factor: 8.327
Authors: Gus Koerbin; Jillian R Tate; Julie Ryan; Graham Rd Jones; Ken A Sikaris; David Kanowski; Maxine Reed; Janice Gill; George Koumantakis; Tina Yen; Andrew St John; Peter E Hickman; Aaron Simpson; Peter Graham Journal: Clin Biochem Rev Date: 2014-11
Authors: Esmee C M Kooijmans; Helena J H van der Pal; Saskia M F Pluijm; Margriet van der Heiden-van der Loo; Leontien C M Kremer; Dorine Bresters; Eline van Dulmen-den Broeder; Marry M van den Heuvel-Eibrink; Jacqueline J Loonen; Marloes Louwerens; Sebastian J C Neggers; Cécile Ronckers; Wim J E Tissing; Andrica C H de Vries; Gertjan J L Kaspers; Arend Bökenkamp; Margreet A Veening Journal: Cancers (Basel) Date: 2022-06-01 Impact factor: 6.575