C Perich1, C Ricós2, V Alvarez3, C Biosca4, B Boned5, F Cava6, M V Doménech7, P Fernández-Calle8, P Fernández-Fernández9, J V García-Lario10, J Minchinela11, M Simón12, R Jansen13. 1. SEQC-Analytical Quality Commission, Barcelona, Spain; Laboratori Clínic Bon Pastor, Barcelona, Spain. 2. SEQC-Analytical Quality Commission, Barcelona, Spain. Electronic address: carmen.ricos@terra.com. 3. SEQC-Analytical Quality Commission, Barcelona, Spain; Laboratori Clínic L'Hospitalet, Hospitalet de Llobregat, Spain. 4. SEQC-Analytical Quality Commission, Barcelona, Spain; Hospital Germans Trias i Pujol, Badalona, Spain. 5. SEQC-Analytical Quality Commission, Barcelona, Spain; Hospital Royo Villanova, Zaragoza, Spain. 6. SEQC-Analytical Quality Commission, Barcelona, Spain; Hospital Universitario Fundación Alcorcón, Madrid, Spain. 7. SEQC-Analytical Quality Commission, Barcelona, Spain; Laboratori Clínic Manso, Barcelona, Spain. 8. SEQC-Analytical Quality Commission, Barcelona, Spain; Hospital Universitario La Paz, Madrid, Spain. 9. SEQC-Analytical Quality Commission, Barcelona, Spain; Laboratoris Clínics Hospital Vall d'Hebron, Barcelona, Spain. 10. SEQC-Analytical Quality Commission, Barcelona, Spain; Hospital Universitario Virgen de las Nieves, Granada, Spain. 11. SEQC-Analytical Quality Commission, Barcelona, Spain; Laboratori Clínic Barcelonès Nord i Vallès Oriental, Badalona, Spain. 12. SEQC-Analytical Quality Commission, Barcelona, Spain; Consorci del Laboratori Intercomarcal de l'Alt Penedès, l'Anoia i el Garraf, Barcelona, Spain. 13. SKML Dutch Foundation for Quality Assessment in Medical Laboratories, Nijmegen, The Netherlands.
Abstract
INTRODUCTION: Current external quality assurance schemes have been classified into six categories, according to their ability to verify the degree of standardization of the participating measurement procedures. SKML (Netherlands) is a Category 1 EQA scheme (commutable EQA materials with values assigned by reference methods), whereas SEQC (Spain) is a Category 5 scheme (replicate analyses of non-commutable materials with no values assigned by reference methods). AIM: The results obtained by a group of Spanish laboratories participating in a pilot study organized by SKML are examined, with the aim of pointing out the improvements over our current scheme that a Category 1 program could provide. METHOD: Imprecision and bias are calculated for each analyte and laboratory, and compared with quality specifications derived from biological variation. RESULTS: Of the 26 analytes studied, 9 had results comparable with those from reference methods, and 10 analytes did not have comparable results. The remaining 7 analytes measured did not have available reference method values, and in these cases, comparison with the peer group showed comparable results. The reasons for disagreement in the second group can be summarized as: use of non-standard methods (IFCC without exogenous pyridoxal phosphate for AST and ALT, Jaffé kinetic at low-normal creatinine concentrations and with eGFR); non-commutability of the reference material used to assign values to the routine calibrator (calcium, magnesium and sodium); use of reference materials without established commutability instead of reference methods for AST and GGT, and lack of a systematic effort by manufacturers to harmonize results. CONCLUSIONS: Results obtained in this work demonstrate the important role of external quality assurance programs using commutable materials with values assigned by reference methods to correctly monitor the standardization of laboratory tests with consequent minimization of risk to patients.
INTRODUCTION: Current external quality assurance schemes have been classified into six categories, according to their ability to verify the degree of standardization of the participating measurement procedures. SKML (Netherlands) is a Category 1 EQA scheme (commutable EQA materials with values assigned by reference methods), whereas SEQC (Spain) is a Category 5 scheme (replicate analyses of non-commutable materials with no values assigned by reference methods). AIM: The results obtained by a group of Spanish laboratories participating in a pilot study organized by SKML are examined, with the aim of pointing out the improvements over our current scheme that a Category 1 program could provide. METHOD: Imprecision and bias are calculated for each analyte and laboratory, and compared with quality specifications derived from biological variation. RESULTS: Of the 26 analytes studied, 9 had results comparable with those from reference methods, and 10 analytes did not have comparable results. The remaining 7 analytes measured did not have available reference method values, and in these cases, comparison with the peer group showed comparable results. The reasons for disagreement in the second group can be summarized as: use of non-standard methods (IFCC without exogenous pyridoxal phosphate for AST and ALT, Jaffé kinetic at low-normal creatinine concentrations and with eGFR); non-commutability of the reference material used to assign values to the routine calibrator (calcium, magnesium and sodium); use of reference materials without established commutability instead of reference methods for AST and GGT, and lack of a systematic effort by manufacturers to harmonize results. CONCLUSIONS: Results obtained in this work demonstrate the important role of external quality assurance programs using commutable materials with values assigned by reference methods to correctly monitor the standardization of laboratory tests with consequent minimization of risk to patients.
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