External Quality Assessment in The Netherlands: time to introduce commutable survey specimens. Lessons from the Dutch “Calibration 2000” project
-
Henk Baadenhuijsen
Abstract
The performance of suitable secondary reference material for the use of trueness control of six routinely measured clinical enzymes in the Dutch External Quality Assessment (EQA) scheme is described. The reference material of choice was selected using the split-patient-sample between-field method (twin study) design as described in an earlier study of the Calibration 2000 project in The Netherlands. This material, which was proven to be commutable for all wet chemistry systems, was implemented as the national enzyme calibrator. It consisted of a cryo-protected lyophilised serum with additions of recombinant human enzymes. Various batches of the frozen version of this material without cryo-protection additive, called native EQA samples, were used in the general EQA scheme for performance evaluation. The results of Calibration 2000 calibrated and non-Calibration 2000 calibrated laboratories were compared for both the regular (spiked with non-human enzymes) and native EQA samples in terms of precision and bias with established reference method values for the native samples. The regular samples showed mean between-laboratory CV ranges for all six enzymes involved (low–high) of 5.5–10.3% for the non-calibrated users vs. 4.6–10.8% for the calibrated users. For the native samples these respective ranges were 5.2–9.9% vs. 2.2–4.9%. Without exception, the group of Calibration 2000 calibrated users showed the lowest bias against the reference method values. Regular EQA samples (spiked with non-human enzymes) showed poorer performance than native samples and are not suitable for accuracy assessment purposes, the main aim of EQA schemes. Native samples that are commutable should be used for trueness control in current EQA schemes.
References
1 The Committee on Enzymes of the Scandinavian Society for Clinical Chemistry and Clinical Physiology. Recommended methods for the determination of four enzymes in blood. Scand J Clin Lab Invest 1974;33:287–306. 10.3109/00365517409082499Search in Google Scholar
3 The Committee on Enzymes of the Scandinavian Society for Clinical Chemistry and Clinical Physiology. Recommended methods for the determination of γ-glutamyltransferase in blood. Scand J Clin Lab Invest 1976;36:119–25. 10.3109/00365517609055236Search in Google Scholar
3 The Committee on Enzymes of the Scandinavian Society for Clinical Chemistry and Clinical Physiology. Recommended methods for the determination of creatine kinase in blood modified by the inclusion of EDTA. Scand J Clin Lab Invest 1979;39:1–5. Search in Google Scholar
4 Bergmeyer HU, Hørder M, Rej R. Approved recommendation (1985) on IFCC methods for the measurement of catalytic concentrations of enzymes. Part 2. IFCC method for aspartate aminotransferase (L-aspartate:2-oxoglutarate aminotransferase, EC 2.6.1.1). J Clin Chem Clin Biochem 1986; 24: 497–510. Search in Google Scholar
5 Bergmeyer HU, Hørder M, Rej R. Approved recommendation (1985) on IFCC methods for the measurement of catalytic concentrations of enzymes. Part 3. IFCC method for alanine aminotransferase (L-alanine:2-oxoglutarate aminotransferase, EC 2.6.1.2). J Clin Chem Clin Biochem 1986; 24: 481–95. Search in Google Scholar
6 Shaw LM, Strømme JH, London JL, Theodorsen L. IFCC methods for the measurement of catalytic concentrations of enzymes. Part 4. IFCC method for γ-glutamyltrans-ferase [(γ-glutamyl)-peptide: amino acid γ-glutamyltransferase, EC 2.3.2.2]. J Clin Chem Clin Biochem 1983; 21: 633–46. Search in Google Scholar
7 Hørder M, Elser RC, Gerhardt W, Mathieu M, Sampson EJ. Approved recommendation (1985) on IFCC methods for the measurement of catalytic concentrations of enzymes. Part 7. IFCC method for creatine kinase (ATP:creatinine N-phosphotransferase, EC 2.7.3.2). J Clin Chem Clin Biochem 1991; 29: 435–56. Search in Google Scholar
8 Bais R, Philcox M. Approved recommendation on IFCC methods for the measurement of catalytic concentrations of enzymes. Part 8. IFCC method for lactate dehydrogenase (L-lactate:NAD + oxidoreductase, EC 1.1.1.27). Eur J Clin Chem Clin Biochem 1994; 32: 639–55. Search in Google Scholar
9 Lorentz K. Approved recommendation on IFCC methods for the measurement of catalytic concentrations of enzymes. Part 9. IFCC method for α-amylase (1,4-α-D-glucan-4-glucanohydrolase, EC 3.2.1.1). Clin Chem Lab Med 1998; 36: 185–203. 10.1515/CCLM.1998.034Search in Google Scholar
10 Grannis GF, Massion CG, Batsakis JG. The 1978 College of American Pathologists survey of analysis of five serum enzymes by 450 laboratories. Am J Clin Pathol 1979; 72: 285–98. Search in Google Scholar
11 Jansen RT, Jansen AP. Standards versus standardized methods in enzyme assay. Ann Clin Biochem 1983; 20: 52–9. 10.1177/000456328302000108Search in Google Scholar
12 Müller MM. Implementation of reference systems in laboratory medicine. Clin Chem 2000; 46: 1907–9. 10.1093/clinchem/46.12.1907Search in Google Scholar
13 Panteghini M, Ceriotti F, Schumann G, Siekmann L. Establishing a reference system in clinical enzymology. Clin Chem Lab Med 2001; 39: 795–800. 10.1515/CCLM.2001.131Search in Google Scholar
14 EU Lex. Directive 98/79 EC on in vitro medical devices. Off J L 1998;331:1–37. Search in Google Scholar
15 Lessinger JM, Férard G, Grafmeyer D, Labbé D, Maire I, Schiele F, et al. Usefulness of reference materials in calibration of enzyme activities. Eur J Clin Chem Clin Biochem 1995; 33: 859–64. 10.1515/cclm.1995.33.11.859Search in Google Scholar
16 Franzini C, Ceriotti F. Impact of reference materials on accuracy in clinical chemistry. Clin Biochem 1998; 31: 449–57. 10.1016/S0009-9120(98)00054-XSearch in Google Scholar
17 Baadenhuijsen H, Steigstra H, Cobbaert C, Kuypers A, Weykamp C, Jansen R. Commutability assessment of potential reference material using a split-patient-sample between-field methods (twin-study) design: study within the framework of the Dutch project “Calibration 2000”. Clin Chem 2002; 48: 1521–25. 10.1093/clinchem/48.9.1520Search in Google Scholar
18 Aoki R, Misaka H, Ueda S. Enzyme reference materials from recombinant cells of human enzyme and human tissue sources. In: Martin SM, Halloran SP, editors. Proceedings of the XVI International Congress of Clinical Chemistry, 8–12 July 1996, London. London: Association of Clinical Biochemists, 1996:50. Search in Google Scholar
19 Baadenhuijsen H, Demacker PN, Hessels M, Boerma GJ, Penders TJ, Weykamp C, et al. Testing the accuracy of total cholesterol assays in an external quality-control program: effect of adding sucrose to lyophilized control sera compared with use of fresh or frozen serum. Clin Chem 1995; 41: 724–30. 10.1093/clinchem/41.5.724Search in Google Scholar
20 Steigstra H, Jansen RTP, Baadenhuijsen H. Combi scheme: new combined internal/external quality assessment scheme in The Netherlands. Clin Chem 1991; 37: 1196–204. 10.1093/clinchem/37.7.1196Search in Google Scholar
21 Ricos C, Alvarez V, Cava F, Garcia-Lario JV, Hernandez A, Jimenez CV, et al. Current databases on biologic variation: pros, cons and progress. Scand J Clin Lab Invest 1999; 59: 491–500. 10.1080/00365519950185229Search in Google Scholar PubMed
22 National Committee for Clinical Laboratory Standards. Evaluation of matrix effects; approved guideline. NCCLS document EP14A. Wayne, PA: NCCLS, 1999. Search in Google Scholar
23 Scharnhorst V, Apperloo J, Baadenhuijsen H, Vader HL. Multicenter evaluation of the commutability of a potential reference material for harmonization of enzyme activities. Clin Chem Lab Med 2004; 4: 1401–7. 10.1515/CCLM.2004.261Search in Google Scholar PubMed
24 Ross JW, Miller WG, Myers GL, Praestguard J. The accuracy of laboratory measurements in clinical chemistry. Arch Pathol Lab Med 1998; 122: 587–608. Search in Google Scholar
25 Thienpont LM, Stöckl D, Friedecky B, Kratochvila J, Budina M. Trueness verification in European external quality assessment schemes: time to care about the quality of samples. Scand J Clin Lab Invest 2003; 63: 195–202. 10.1080/00365510310000349Search in Google Scholar PubMed
©2005 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Effect of stress doses of hydrocortisone on S-100B vs. interleukin-8 and polymorphonuclear elastase levels in human septic shock
- Conjugated linoleic acid suppresses the secretion of atherogenic lipoproteins from human HepG2 liver cells
- Determination of debrisoquine and 4-hydroxydebrisoquine by high-performance liquid chromatography: application to the evaluation of CYP2D6 genotype and debrisoquine metabolic ratio relationship
- Assessment of iodine intake in mildly iodine-deficient pregnant women by a new automated kinetic urinary iodine determination method
- Butyrylcholinesterase activity and metabolic syndrome in obese patients
- The non-thyroidal illness syndrome after coronary artery bypass grafting: a 6-month follow-up study
- Advanced oxidation protein products (AOPP) for monitoring oxidative stress in critically ill patients: a simple, fast and inexpensive automated technique
- Quality control in urinary stone analysis: results of 44 ring trials (1980–2001)
- External Quality Assessment in The Netherlands: time to introduce commutable survey specimens. Lessons from the Dutch “Calibration 2000” project
- Evaluation of a high-sensitivity turbidimetric immunoassay for serum C-reactive protein: application to the study of longitudinal changes throughout normal pregnancy
- A quantitative appraisal of interference by icodextrin metabolites in point-of-care glucose analyses
- Preanalytical variability in laboratory testing: influence of the blood drawing technique
- Soluble transferrin receptor and transferrin receptor-ferritin index in iron deficiency anemia and anemia in rheumatoid arthritis
- Elevated plasma cysteinylglycine levels caused by cilastatin-associated antibiotic treatment
- The number of consultant clinical chemists in the 15-nation European Union
- Biological variation of vascular endothelial growth factor
- Terminology, categories and representation of examinations in laboratory medicine
- Reply to W.G. Wood. Questionable results – who directs the EQAS organisers? Clin Chem Lab Med 2004;42:1073
- The predictive power of serum κ/λ ratios for discrimination between monoclonal gammopathy of undetermined significance and multiple myeloma
- 4th Conference on Hyperhomocysteinemia: Saarbrücken, Germany, April, 14–16, 2005, Saarland University
Articles in the same Issue
- Effect of stress doses of hydrocortisone on S-100B vs. interleukin-8 and polymorphonuclear elastase levels in human septic shock
- Conjugated linoleic acid suppresses the secretion of atherogenic lipoproteins from human HepG2 liver cells
- Determination of debrisoquine and 4-hydroxydebrisoquine by high-performance liquid chromatography: application to the evaluation of CYP2D6 genotype and debrisoquine metabolic ratio relationship
- Assessment of iodine intake in mildly iodine-deficient pregnant women by a new automated kinetic urinary iodine determination method
- Butyrylcholinesterase activity and metabolic syndrome in obese patients
- The non-thyroidal illness syndrome after coronary artery bypass grafting: a 6-month follow-up study
- Advanced oxidation protein products (AOPP) for monitoring oxidative stress in critically ill patients: a simple, fast and inexpensive automated technique
- Quality control in urinary stone analysis: results of 44 ring trials (1980–2001)
- External Quality Assessment in The Netherlands: time to introduce commutable survey specimens. Lessons from the Dutch “Calibration 2000” project
- Evaluation of a high-sensitivity turbidimetric immunoassay for serum C-reactive protein: application to the study of longitudinal changes throughout normal pregnancy
- A quantitative appraisal of interference by icodextrin metabolites in point-of-care glucose analyses
- Preanalytical variability in laboratory testing: influence of the blood drawing technique
- Soluble transferrin receptor and transferrin receptor-ferritin index in iron deficiency anemia and anemia in rheumatoid arthritis
- Elevated plasma cysteinylglycine levels caused by cilastatin-associated antibiotic treatment
- The number of consultant clinical chemists in the 15-nation European Union
- Biological variation of vascular endothelial growth factor
- Terminology, categories and representation of examinations in laboratory medicine
- Reply to W.G. Wood. Questionable results – who directs the EQAS organisers? Clin Chem Lab Med 2004;42:1073
- The predictive power of serum κ/λ ratios for discrimination between monoclonal gammopathy of undetermined significance and multiple myeloma
- 4th Conference on Hyperhomocysteinemia: Saarbrücken, Germany, April, 14–16, 2005, Saarland University
