An approach to establish the uncertainty budget of catalytic activity concentration measurements in a reference laboratory
-
Laura Rami
Abstract
Background: Reference laboratories providing reference services recognized by the Joint Committee for Traceability in Laboratory Medicine (JCTLM) must be accredited as calibration laboratories according to ISO 17025 and ISO 15195. These standards require laboratories to establish an uncertainty budget, in which the uncertainty contributions of the relevant uncertainty components are specified. We present a model to estimate the measurement uncertainty of creatine kinase catalytic activity concentration results obtained by IFCC primary reference measurement procedure.
Methods: The measurement uncertainty has been estimated by following the next steps: 1) specification of the measurand; 2) identification of the most relevant uncertainty sources; 3) estimation of standard uncertainties by either type A or type B evaluation; 4) estimation of combined uncertainty while taking into account sensitivity coefficients, as well as existence of correlated uncertainty sources; and 5) estimation of expanded uncertainty with a defined coverage probability.
Results: The estimated expanded uncertainty was 2.2% (k=2). Uncertainty sources with a significant contribution to the measurement uncertainty were the following: pH adjustment (0.68%), absorbance accuracy (0.48%), wavelength adjustment (0.20%), reaction temperature (0.19%), volume fraction of sample (0.15%) and absorbance linearity (0.06%).
Conclusions: The present model is an approach to establish the uncertainty budget of primary reference procedures for the measurement of the catalytic activity concentration of enzymes, and aims at being an example to be followed by other reference laboratories, as well as by laboratories that carry out primary reference measurement procedures.
Acknowledgments
We would like to thank reviewers for their many helpful suggestions and corrections.
Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Financial support: None declared.
Employment or leadership: None declared.
Honorarium: None declared.
Competing interests: The funding organization(s) played no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.
References
1. Armbruster D, Miller RR. The Joint Committee for Traceability in Laboratory Medicine (JCTLM): a global approach to promote the standardisation of clinical laboratory test results. Clin Biochem Rev 2007;28:105–13.Suche in Google Scholar
2. International Organization for Standardization. ISO/IEC 17025:2005. General requirements for the competence of testing and calibration laboratories. Geneva, Switzerland: ISO, 2005.Suche in Google Scholar
3. International Organization for Standardization. ISO 15195:2003. Laboratory medicine – Requirements for reference measurements laboratories. Geneva, Switzerland: ISO, 2003.Suche in Google Scholar
4. RELA – IFCC External quality assessment scheme for reference laboratories in laboratory medicine. Available at: http://www.dgkl-rfb.de:81/. Accessed December, 2013.Suche in Google Scholar
5. Siekmann L. Requirements for reference (calibration) laboratories in laboratory medicine. Clin Biochem Rev 2007;28:149–54.Suche in Google Scholar
6. White GH. Metrological traceability in clinical biochemistry. Ann Clin Biochem 2011;48:393–409.10.1258/acb.2011.011079Suche in Google Scholar PubMed
7. 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.2001.131Suche in Google Scholar PubMed
8. Joint Committee for Guides in Metrology. International vocabulary of metrology. Basic and general concepts and associated terms (VIM). JCGM 200:2012. Available at: http://www.bipm.org/en/publications/guides/vim.html. Accessed January, 2014.Suche in Google Scholar
9. Joint Committee for Guides in Metrology. Evaluation of measurement data – Guide to the expression of uncertainty in measurement (GUM). JCGM 100:2008. Available at: http://www.bipm.org/en/publications/guides/gum.html. Accessed October, 2013.Suche in Google Scholar
10. Laboratori de Referència d’Enzimologia Clínica. Available at: http://sct.uab.cat/lrec/. Accessed February, 2014.Suche in Google Scholar
11. Schumann G, Bonora R, Ceriotti F, Clerc-Renaud P, Ferrero CA, Férard G, et al. IFCC primary reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 °C, Part 2. Reference procedure for the measurement of catalytic concentration of creatine kinase. Clin Chem Lab Med 2002;40:635–42.10.1515/CCLM.2002.110Suche in Google Scholar PubMed
12. EURACHEM/CITAC Guide. Quantifying uncertainty in analytical measurement, 3er ed. Eurachem, 2012. Available at: http://www.eurachem.org/. Accessed February, 2014.Suche in Google Scholar
13. International Organization for Standardization. ISO 18153:2003. In vitro diagnostic medical devices – measurement of quantities in biological samples – metrological traceability of values for catalytic concentration of enzymes assigned to calibrators and control materials. Geneva, Switzerland: ISO, 2003.Suche in Google Scholar
14. Park J, Nam G, Choi J. Parameters in cause and effect diagram for uncertainty evaluation. Accred Qual Assur 2011;16:325–6.10.1007/s00769-011-0763-4Suche in Google Scholar
15. Clinical and Laboratory Standards Institute. Expression of measurement uncertainty in laboratory medicine; Approved Guideline. CLSI document EP29-A. Wayne: CLSI, 2012.Suche in Google Scholar
16. Kristiansen J. Description of a generally applicable model for the evaluation of uncertainty of measurement in clinical chemistry. Clin Chem Lab Med 2001;39:920–31.10.1515/CCLM.2001.148Suche in Google Scholar PubMed
17. Ramamohan V, Yih Y, Abbott JT, Klee GG. Category-specific uncertainty modeling in clinical laboratory measurement processes. Clin Chem Lab Med 2013;51:2273–80.10.1515/cclm-2013-0357Suche in Google Scholar PubMed
18. Farrance I, Frenkel R. Uncertainty of measurement: a review of rules for calculating uncertainty components through functional relationships. Clin Biochem Rev 2012;33:49–75.Suche in Google Scholar
19. International Organization for Standardization. ISO/TS 21748:2004. Guidance for the use of repeatability, reproducibility and trueness estimates in measurement uncertainty estimation. Geneva, Switzerland: ISO, 2004.Suche in Google Scholar
20. Kallner A. Estimation of uncertainty in measurements in the clinical laboratory. Clin Chem Lab Med 2013;51:2249–51.10.1515/cclm-2013-0749Suche in Google Scholar PubMed
21. Rami L, Canalias F. Estimación de la incertidumbre de medida de un procedimiento de referencia primario para la medición de actividad catalítica. Lab Clín 2011;4:255.Suche in Google Scholar
22. Schumann G, Canalias F, Joergensen PJ, Kang D, Lessinger JM, Klauke R, et al. IFCC reference procedures for measurement of catalytic concentrations of enzymes: corrigendum, notes and useful advice. Clin Chem Lab Med 2010;48:615–21.10.1515/CCLM.2010.137Suche in Google Scholar PubMed
©2015 by De Gruyter
Artikel in diesem Heft
- Frontmatter
- Editorial
- High-sensitivity assays for cardiac troponins
- Reviews
- High sensitivity cardiac troponin assays in the clinical laboratories
- Laboratory medicine as the science that underpins medicine: the “high-sensitivity” troponin paradigm
- Cardiac troponin assays: a review of quantitative point-of-care devices and their efficacy in the diagnosis of myocardial infarction
- Cardiovascular Diseases
- Evaluation of standardization capability of current cardiac troponin I assays by a correlation study: results of an IFCC pilot project
- Estimation of age- and comorbidities-adjusted percentiles of high-sensitivity cardiac troponin T levels in the elderly
- High-sensitivity cardiac troponin I in the general population – defining reference populations for the determination of the 99th percentile in the Gutenberg Health Study
- Kinetics of high-sensitivity cardiac troponin T or troponin I compared to creatine kinase in patients with revascularized acute myocardial infarction
- Biological variation of high sensitivity cardiac troponin-T in stable dialysis patients: implications for clinical practice
- Diagnosis of acute myocardial infarction in patients with renal insufficiency using high-sensitivity troponin T
- General Clinical Chemistry and Laboratory Medicine
- Active intervention in hospital test request panels pays
- An approach to establish the uncertainty budget of catalytic activity concentration measurements in a reference laboratory
- Uric acid: a potential biomarker of multiple sclerosis and of its disability
- Experience with the first fully automated chemiluminescence immunoassay for the quantification of 1α, 25-dihydroxy-vitamin D
- I-FABP and L-FABP are early markers for abdominal injury with limited prognostic value for secondary organ failures in the post-traumatic course
- Quantification of piperacillin, tazobactam, cefepime, meropenem, ciprofloxacin and linezolid in serum using an isotope dilution UHPLC-MS/MS method with semi-automated sample preparation
- Plasma visfatin/nicotinamide phosphoribosyltransferase (visfatin/NAMPT) concentration is not related to kidney function in elderly subjects
- Diagnostic performance study of an antigen microarray for the detection of antiphospholipid antibodies in human serum
- Dry ice exposure of plasma samples influences pH and lupus anticoagulant analysis
- Reference Values and Biological Variations
- A new robust statistical model for interpretation of differences in serial test results from an individual
- Cancer Diagnostics
- The value of red blood cell distribution width in endometrial cancer
- Letters to the Editors
- Serum high-sensitivity troponin concentrations in a multi-ethnic Asian population of stable chronic kidney disease patients
- Comparison between BNP values measured in capillary blood samples with a POCT method and those measured in plasma venous samples with an automated platform
- Reply to the article entitled “Impact of assay design on test performance: lessons learned from 25-hydroxyvitamin D” by Farrell et al., Clin Chem Lab Med 2014;52:1579–87
- Reply. Impact of assay design on test performance: lessons learned from 25-hydroxyvitamin D. Authors’ response to the Letter to the Editor by Donnelly et al.
- Therapeutic drug monitoring of voriconazole: validation of a novel ARK™ immunoassay and comparison with ultra-high performance liquid chromatography
- Interference of C-reactive protein with clotting times
Artikel in diesem Heft
- Frontmatter
- Editorial
- High-sensitivity assays for cardiac troponins
- Reviews
- High sensitivity cardiac troponin assays in the clinical laboratories
- Laboratory medicine as the science that underpins medicine: the “high-sensitivity” troponin paradigm
- Cardiac troponin assays: a review of quantitative point-of-care devices and their efficacy in the diagnosis of myocardial infarction
- Cardiovascular Diseases
- Evaluation of standardization capability of current cardiac troponin I assays by a correlation study: results of an IFCC pilot project
- Estimation of age- and comorbidities-adjusted percentiles of high-sensitivity cardiac troponin T levels in the elderly
- High-sensitivity cardiac troponin I in the general population – defining reference populations for the determination of the 99th percentile in the Gutenberg Health Study
- Kinetics of high-sensitivity cardiac troponin T or troponin I compared to creatine kinase in patients with revascularized acute myocardial infarction
- Biological variation of high sensitivity cardiac troponin-T in stable dialysis patients: implications for clinical practice
- Diagnosis of acute myocardial infarction in patients with renal insufficiency using high-sensitivity troponin T
- General Clinical Chemistry and Laboratory Medicine
- Active intervention in hospital test request panels pays
- An approach to establish the uncertainty budget of catalytic activity concentration measurements in a reference laboratory
- Uric acid: a potential biomarker of multiple sclerosis and of its disability
- Experience with the first fully automated chemiluminescence immunoassay for the quantification of 1α, 25-dihydroxy-vitamin D
- I-FABP and L-FABP are early markers for abdominal injury with limited prognostic value for secondary organ failures in the post-traumatic course
- Quantification of piperacillin, tazobactam, cefepime, meropenem, ciprofloxacin and linezolid in serum using an isotope dilution UHPLC-MS/MS method with semi-automated sample preparation
- Plasma visfatin/nicotinamide phosphoribosyltransferase (visfatin/NAMPT) concentration is not related to kidney function in elderly subjects
- Diagnostic performance study of an antigen microarray for the detection of antiphospholipid antibodies in human serum
- Dry ice exposure of plasma samples influences pH and lupus anticoagulant analysis
- Reference Values and Biological Variations
- A new robust statistical model for interpretation of differences in serial test results from an individual
- Cancer Diagnostics
- The value of red blood cell distribution width in endometrial cancer
- Letters to the Editors
- Serum high-sensitivity troponin concentrations in a multi-ethnic Asian population of stable chronic kidney disease patients
- Comparison between BNP values measured in capillary blood samples with a POCT method and those measured in plasma venous samples with an automated platform
- Reply to the article entitled “Impact of assay design on test performance: lessons learned from 25-hydroxyvitamin D” by Farrell et al., Clin Chem Lab Med 2014;52:1579–87
- Reply. Impact of assay design on test performance: lessons learned from 25-hydroxyvitamin D. Authors’ response to the Letter to the Editor by Donnelly et al.
- Therapeutic drug monitoring of voriconazole: validation of a novel ARK™ immunoassay and comparison with ultra-high performance liquid chromatography
- Interference of C-reactive protein with clotting times
