IFCC Working Group Recommendations for assessing commutability part 2: Using the Difference in Bias Between a Reference Material and Clinical Samples

A process is described to assess the commutability of a reference material intended for use as a calibrator, trueness control or external quality assessment sample based on the difference in bias between a reference material and clinical samples measured using two different measuring systems. This difference in bias is compared to a criterion based on a medically relevant difference between a reference material and clinical sample results to make a conclusion regarding commutability. When more than two measuring systems are included, the commutability is assessed pair-wise for all combinations of two measuring systems. This approach allows the same criterion to be used for all combinations of measuring systems included in the assessment. The assessment is based on an error model that allows estimation of various random and systematic sources of error including that from sample specific effects of interfering substances. An advantage of this approach is that the difference in bias between a reference material and the average bias of clinical samples at the concentration (i.e. amount of substance present or quantity value) of the reference material is determined and its uncertainty estimated. A reference material is considered fit for purpose for those measuring systems where commutability is demonstrated.

NILSSON Goran;  BUDD Jeffrey;  GREENBERG Neel;  DELATOUR Vincent;  REJ Robert;  PANTEGHINI M.;  CERIOTTI Ferruccio;  SCHIMMEL Heinz;  WEYKAMP Cas;  KELLER Thomas;  CAMARA Johanna;  BURNS Chris;  VESPER Hubert;  MACKENZIE Finlay;  MILLER W. Greg; 

2018-02-16

AMER ASSOC CLINICAL CHEMISTRY

JRC106619

0009-9147,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC106619,   

10.1373/clinchem.2017.277541,