Trueness evaluation and verification of inter-assay agreement of serum folate measuring systems
Articolo
Data di Pubblicazione:
2020
Citazione:
Trueness evaluation and verification of inter-assay agreement of serum folate measuring systems / F. Braga, E. Frusciante, S. Ferraro, M. Panteghini. - In: CLINICAL CHEMISTRY AND LABORATORY MEDICINE. - ISSN 1437-4331. - 58:10(2020), pp. 1697-1705. [10.1515/cclm-2019-0928]
Abstract:
Background: Definitive data to establish if the use of the WHO International Standard (IS) 03/178 as a common calibrator of commercial measuring systems (MSs) has improved the harmonization of serum total folate (tFOL) measurements to a clinically suitable level are lacking.
Here, we report the results of an intercomparison study aimed to verify if the current inter-assay variability is acceptable for clinical application of tFOL testing.
Methods: After confirming their commutability, the IS 03/178 and National Institute for Standards and Technology SRM 3949 L1 were used for evaluating the correctness of traceability implementation by manufacturers and the MSs trueness, respectively. The inter-assay agreement was verified using 20 patient pools. The measurement uncertainty (U) of tFOL measurements on clinical samples was also estimated. An outcome-based model for defining desirable performance specifications for bias and imprecision for serum tFOL measurements was applied.
Results: The majority of evaluated MSs overestimated the WHO IS value of +5% or more with the risk to produce an unacceptably high number of false-negative results in clinical practice. The mean inter-assay CV on all pools and on those with tFOL values >3.0 μg/L (n = 15) was 12.5% and 7.1%, respectively. In neither case the goal of 3.0% was fulfilled. The residual bias resulted in an excessive U of tFOL
measurement on clinical samples.
Conclusions: The implementation of traceability of tFOL MSs to the WHO IS 03/178 is currently inadequate, resulting in an inter-assay variability that does not permit the use of a common threshold for detecting folate deficiency.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
decision-making; standardization; total folate; trueness
Elenco autori:
F. Braga, E. Frusciante, S. Ferraro, M. Panteghini
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