Interchangeability of Estimates of Day-to-Day Imprecision between Commercial Control Materials and Serum Pools

Reducing the effects of control materials based on interchangeability of estimates of day‐to‐day imprecision between commercial control materials and serum samples

“…In addition to the matrix effect, the likely causes of the statistical difference in the imprecision between the commercial control materials and the serum samples include 3,4,6 (1) variations in the preparation and reconstitution of the control material (ie, the variations between bottles); (2) differences in the stability of the two samples, which affected factors that included sample moisture evaporation, storage temperature, the freeze-thaw process; (3) insufficient sample mixing.…”

“…In addition, if the noninterchangeability were found among control materials from different manufacturers or, worse still, among different lots of the same control material, monitoring day‐to‐day imprecision during long periods also would be very difficult 4 . Consequently, it is very important to strive to make the control materials have the imprecision interchangeable with the human samples.…”

Commutability and interchangeability of commercial quality control materials with feline plasma for common biochemical analytes

“…There appears to be a contradiction between the definition of commutability as “the equivalence of the mathematical relationships between the results of different measurement procedures” for a QCM and patient samples and the recognized processes to determine commutability as “the equivalence” does not extend to precision. Statistically significant differences in the precision between commercial QCM and patient samples indicate noninterchangeability, but have received little attention, even within human clinical pathology . Noninterchangeability affects daily QA and method comparison studies in reference, practice, and research laboratories.…”

“…Interchangeability refers to the similarities of precision between QCM and patient samples and has so far received little attention, even within human clinical pathology . Precision has previously been compared by using an F‐test to assess differences in SD .…”

“…Interchangeability refers to the similarities of precision between QCM and patient samples and has so far received little attention, even within human clinical pathology . Precision has previously been compared by using an F‐test to assess differences in SD . The coefficient of variation (CV) obtained for repeat QCM analyte measurements can be compared to CV from repeat analyte measurements in normal or patient plasma pools using a bootstrap method …”