Measurement uncertainty for clinical laboratories – a revision of the concept
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Graham Ross Dallas Jones
Abstract
The uncertainty of a measurement result is a fundamental concept in metrology indicating the range within the “true” value of a measurement should lie. Although not commonly reported with results, the calculation of measurement uncertainty (MU) has become common in routine clinical laboratories. Interpretation of numerical pathology results is made by comparison with data from other measurements. As MU is aimed at assisting with result interpretation, it should be related to the specific comparison being made. There are three basic type of comparators: a previous result from the same patient, a population reference interval, or a clinical decision point. For each comparison, the “true” value is that which would have been obtained from the instrument used to make the comparator measurements if it was measured without uncertainty. The MU is the range of likely deviations from this true value due to the method used to produce the result under interpretation. For patient monitoring, if the two measurements were made on the same analyzer, the uncertainty is the imprecision of the assay over the relevant time frame. In comparing with a manufacturer-specific reference interval, the MU is deviation from the manufacturer’s master calibrator. For clinical decision points produced with the assays traceable to international references, the MU is related to deviation from that reference standard. For optimal use of MU in the clinical laboratory, it may be necessary to consider the use of the test result and the concept of a single MU for each result may need to be revised.
Author contributions: The author has accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: None declared.
Employment or leadership: None declared.
Honorarium: None declared.
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©2016 by De Gruyter
Artikel in diesem Heft
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Artikel in diesem Heft
- Frontmatter
- Editorials
- Laboratory analytical quality – the process continues
- Measurement uncertainty – a revised understanding of its calculation and use
- Review
- Substrate-zymography: a still worthwhile method for gelatinases analysis in biological samples
- Opinion Papers
- Is the combination of trueness and precision in one expression meaningful? On the use of total error and uncertainty in clinical chemistry
- The problem with total error models in establishing performance specifications and a simple remedy
- Measurement uncertainty for clinical laboratories – a revision of the concept
- Uncertainty in measurement and total error – are they so incompatible?
- General Clinical Chemistry and Laboratory Medicine
- Using the hazard ratio to evaluate allowable total error in predictive measurands
- Performance of electrolyte measurements assessed by a trueness verification program
- Analytical interference by monoclonal immunoglobulins on the direct bilirubin AU Beckman Coulter assay: the benefit of unsuspected diagnosis from spurious results
- Preliminary probe of quality indicators and quality specification in total testing process in 5753 laboratories in China
- Analytical and clinical evaluation of the new Fujirebio Lumipulse®G non-competitive assay for 25(OH)-vitamin D and three immunoassays for 25(OH)D in healthy subjects, osteoporotic patients, third trimester pregnant women, healthy African subjects, hemodialyzed and intensive care patients
- Patient-performed extraction of faecal calprotectin
- Comparison of the clinical utility of the Elia CTD Screen to indirect immunofluorescence on Hep-2 cells
- Reference Values and Biological Variations
- Sex-related differences in the association of ghrelin levels with obesity in adolescents
- Gestation specific reference intervals for thyroid function tests in pregnancy
- Cancer Diagnostics
- SOX17 promoter methylation in plasma circulating tumor DNA of patients with non-small cell lung cancer
- Dopamine concentration in blood platelets is elevated in patients with head and neck paragangliomas
- Letters to the Editor
- Cancer dynamics and the success of cancer screening programs
- Mother’s instinct – a rare case of multiple test interferences due to heterophile antibodies
- Sigma metric or defects per million opportunities (DPMO): the performance of clinical laboratories should be evaluated by the Sigma metrics at decimal level with DPMOs
- A national survey of preanalytical handling of oral glucose tolerance tests in pregnancy
- Updating pregnancy diabetes guidelines: is (y)our laboratory ready?
- Low serum bilirubin values are associated with pulmonary embolism in a case-control study
- Effect of Hb H on HbA1c measurements as measured by IFCC reference method and affinity HPLC
- Adipocytes in venipunctures cause falsely elevated S-100B serum values
- Earlier detection of sepsis by Candida parapsilosis using three-dimensional cytographic anomalies on the Mindray BC-6800 hematological analyzer
- Theranos phenomenon – part 4: Theranos at an International Conference
