NIST Micronutrients Measurement Quality Assurance Program: Characterizing Individual Participant Measurement Performance Over Time

摘要

The mission of the Micronutrients Measurement Quality Assurance Program (M2QAP) at the National Institute of Standards and Technolo~r is enhanced interlaboratory measurement comparability for fat-soluble vitamin-related measurands in human serum. We recently described improved tools for evaluating individual participant mea-surement peiformance in single mterlaboratoiy compari-son exercises; we here apply and extend these tools to the evaluation of participant performance over die entire 15-year history of the M2QAP. We describe and iflustrate a set of interconnected graphical reporting tools for identifying long-term trends and single-exercise events. We document and discuss recurrent patterns we observe in the measurement performance characteristics for M2-QAP participants. The graphical analysis techniques utilized may be applicable to other interlaboratory com-parison programs.