Assessment of the variability of the measurement results obtained by different assays and the effectiveness of standardization is best accomplished through external quality assessment (EQA), or proficiency testing (PT), schemes.[2],[3],[4] The ideal EQA materials and calibrators need to be commutable or the
commutability must be known to ensure that the objective of evaluating the comparability of different assays is fulfilled.[5],[6] However, for practical reasons, most PT schemes use processed materials with unknown
commutability.
With the already described caveat of
commutability, our data show the following sensitivity differences of a magnitude equal to or greater than 1 log: HER2 HercepTest greater than 4B5; PR 16 and 636 greater than 1E2; and ER SP1 greater than 6F11.
At the same time, laboratory professionals may not understand when
commutability of quality control materials should be evaluated, whether control material needs to be traceable for daily operations, or how uncertainty of measurement is relevant to reporting patient results.
Specimen materials, target values and
commutability for external quality assessment (proficiency testing) schemes.
The
commutability of these panels and their utility as secondary IS reference materials have been priorly confirmed in an independent global collaborative trial published last year by the American Association of Clinical Chemistry.
Hashizume et al., "
Commutability of National Institute of Standards and Technology standard reference material 1955 homocysteine and folate in frozen human serum for total folate with automated assays," Annals of Clinical Biochemistry, vol.
Furthermore, these data provide some evidence for
commutability of the candidate standard for evaluation of HEV from infected persons, because samples 1 and 2 represent a different strain of HEV compared with samples 3 and 4.
And parts of it do indeed fit that description-including areas that abut Historic Pullman, whose relative safety,
commutability, and atypical cohesiveness Pearson touts.
This
commutability is precisely the point: Mackie's images all occupy three dimensions, pushing painting into full objecthood just as sculpture may evaporate into the pictorial.
As a generic advertisement, it represents the
commutability of consumer goods notwithstanding the way we fetishize our brands.
"Usually it will be schooling ahead of everything else;
commutability particularly to local towns, Birmingham and a lesser extent London, taking into consideration A-roads, motorway networks and airports such as Birmingham International, and villages and towns with good facilities.
Sam Gibson, partner at Strutt and Parker, which covers an area between the Tweed and Tees, says
commutability is a key factor.
A combination of space, gardens, hobby facilities, views and
commutability put Riding Wood Farm in a rare category.
