Recommendations for Setting a Criterion for Assessing Commutability of Secondary Calibrator Certified Reference Materials

Published

August 11, 2023

Author(s)

W. Greg Miller, Thomas Keller, Jeffrey Budd, Jesper Johansen, Mauro Panteghini, Neil Greenberg, Vincent Delatour, Ferruccio Ceriotti, Robert Rej, Johanna Camara, Liesbet Deprez, Finlay MacKenzie, Alicia Lyle, Eline van der Hagen, Chris Burns, Pernille Fauskanger, Sverre Sandberg

Abstract

A secondary higher-order calibrator is required to be commutable with clinical samples to be suitable for use in the calibration hierarchy of an end-user clinical laboratory in vitro diagnostic medical device (IVD-MD). Commutability is a property of a reference material that means results for a reference material and for clinical samples have the same numeric relationship, within specified limits, across the measurement procedures for which the reference material is intended to be used. Procedures for assessing commutability have been described in the literature. This report provides recommendations for establishing a quantitative criterion to assess the commutability of a certified reference material (CRM). The criterion is the maximum allowable noncommutability bias (MANCB) that allows a CRM to be used as a calibrator in a calibration hierarchy for an IVD-MD without exceeding the maximum allowable combined standard uncertainty for a clinical sample result (umaxCS). Consequently, the MANCB is derived as a fraction of the umaxCS for the measurand. The suitability of an MANCB for practical use in a commutability assessment is determined by estimating the number of measurements of clinical samples and CRMs required based on the precision performance and nonselectivity for the measurand of the measurement procedures in the assessment. Guidance is also provided for evaluating indeterminate commutability conclusions and how to report results of a commutability assessment. The criterion is the maximum allowable noncommutability bias (MANCB) that permits a CRM to be used in calibration hierarchies with that MANCB allowing the IVD-MD to meet the analytical performance specification for the maximum allowable combined standard uncertainty for a clinical sample (MAuCS) result for the measurand. Consequently, the MANCB is derived as a fraction of the MAuCS for the measurand. Once a MANCB is determined, it can be assessed for practical use in a commutability assessment by estimating the number of measurements of clinical samples and CRMs required given the intermediate precision performance and an estimate of any non-selectivity for the measurand of the measuring systems included in the commutability assessment. Guidance is also provided for assessing indeterminate commutability conclusions and how to report results of a commutability assessment.

Citation

Clinical Chemistry

Pub Type

Journals

Download Paper

https://doi.org/10.1093/clinchem/hvad104

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Keywords

Calibration hierarchy, commutability, criterion, metrological traceability, uncertainty

Citation

Miller, W. , Keller, T. , Budd, J. , Johansen, J. , Panteghini, M. , Greenberg, N. , Delatour, V. , Ceriotti, F. , Rej, R. , Camara, J. , Deprez, L. , MacKenzie, F. , Lyle, A. , van der Hagen, E. , Burns, C. , Fauskanger, P. and Sandberg, S. (2023), Recommendations for Setting a Criterion for Assessing Commutability of Secondary Calibrator Certified Reference Materials, Clinical Chemistry, [online], https://doi.org/10.1093/clinchem/hvad104, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=936149 (Accessed April 27, 2024)