Analytical performance specifications for external quality assessment


External quality assessment (EQA) plays an essential role in helping to assure quality in laboratory medicine. Through the appropriate use of EQA schemes laboratory medicine specialists can benchmark the performance of their methods against peers using the same methods. EQA schemes may also reveal significant and systematic between-method variability for measurements of the same analyte in the same specimen. Such between-method variability is a major driver for global method standardization / harmonization projects.

In order to be of maximum benefit to the users of laboratory medicine services, including the patient, it is essential that EQA schemes themselves adhere to high standards. Therefore the article entitled ‘Analytical performance specifications for external quality assessment: - definitions and descriptions’ is a valuable addition to quality and consistency in the operation and use of EQA schemes. The multi-author study, published in the July 2017 issue of Clinical Chemistry & Laboratory Medicine, provides recommendations from the European Federation of Clinical Chemistry & Laboratory Medicine (EFLM) Task and Finish Group on Performance Specifications for External Quality Assurance Schemes.

The recommendations suggest terminology covering six elements required to understand the analytical performance specifications (APS) used by EQA scheme organisers:

  1. A statement on the EQA material matrix and its commutability
  2. The method used to assign the target value
  3. The data set to which the APS are applied
  4. The applicable analytical property being assesses (i.e. total error, bias, imprecision, uncertainty)
  5. The rationale for selection of the APS
  6. The type of the Milan model(s) used to set the APS

The article is essential reading for the providers of EQA and laboratory medicine specialists will find it useful to better understand the EQA schemes in which they participate.

The full reference for the article is:

Jones GRD, Albarede S, Kesseler D, MacKenzie F, Mammen J, Pedersen M et al. ‘Analytical performance specifications for external quality assessment: - definitions and descriptions’. Clin Chem Lab Med 2017; 55(7): 949-955

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