Traceability in Qualitative Analysis

Elvar Theodorsson, Clinical Chemistry, Linköping University, Linköping, Sweden (elvar.theodorsson@liu.se)

The principles for traceability in laboratory medicine are the same for qualitative and quantitative measurement results while the practice including the statistical methods differ. According to the International vocabulary of metrology (VIM), traceability is “a property of a measurement result that can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty”.  In Laboratory Medicine, the reference must be amongst the following: 1) The definition of a SI unit, 2) A certified value of a reference material, 3) The result of a reference measuring system, 4) The value assigned to aninternational conventional reference material, and 5) The values assigned to international harmonization reference materials

The VIM definition of traceability alone is comprehensive in physics where measurements are direct. The quality infrastructure of traceability is self-evident and fulfilled in physics, e.g., when measuring mass, length, time, or temperature. In contrast, the quality infrastructure – known as “pillars of traceability” in Laboratory Medicine must be detailed when claiming traceability since measurements in Laboratory Medicine are usually indirect and influenced by matrix effects. If the quality infrastructure is not detailed in claims of traceability in Laboratory Medicine, “traceability,” like beauty, risks being in the eye of the beholder. 

Traceability in Laboratory Medicine can currently be claimed referring to ISO 17511:2020 and ISO 21151:2020. To what extent regulators and accreditation authorities will demand the fulfillment one or more of the pillars of traceability for valid claims of traceability in Laboratory Medicine remains to be seen.

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Short Biography of Presenting Author

Born in 1953 in Reykjavik, Iceland, Elvar Theodorsson received his M.D. degree in 1978 from the University of Iceland and license as a specialist in clinical pathology (Clinical chemistry) in 1985. He gained his Ph.D. degree from the Department of Pharmacology, Karolinska Institute, Stockholm in 1983 and became an associate professor at the Karolinska Institute in 1986 and Professor of Neurochemistry at the University of Linkoping in 1995. His main research interests include the neuroendocrinology of regulatory peptides and neurosteroids and applied metrology in Clinical Chemistry. http://orcid.org/0000-0003-0756-7723