The commutability and assignment of target values of proficiency testing/external quality assessment sample in clinical laboratory / 中华检验医学杂志

ABSTRACT

Key factors for interpreting proficiency testing (PT)/external quality assessment (EQA) results are knowledge of the commutability of the samples used and the process used for target value assignment.A commutable PT/EQA sample,which would be seen as patients' samples,has the agreement of results among different measurement procedures and demonstrates the same numeric relationship.The value assignment for the sample can be done by using of a reference measurement procedure.Its results can be used to assess the accuracy against a reference measurement procedure or a designated comparison method.Noncommutable PT/EQA samples frequently have a matrix-related bias of unknown magnitude,and can't give meaningful information about the relationship of results for patients' samples among different measurement procedures.Its results must be compared to the peer group mean or the median of results from participants who use measurement procedures that are expected to have the same or very similar matrixrelated bias.