External Quality Assessment of Serum Enzyme Activity Assays and the Effect of Calibration on Interlaboratory Concordance

Abstract

The design and results of a UK external quality assessment scheme for six enzymes are described, from 21 surveys over a period of 7 years. Improvements in interlaboratory agreement and the adoption of reliable methods are documented. The potential of enzyme calibration materials in further improving numerical concordance between laboratories using different assay conditions, including temperature, is demonstrated and discussed.