Trueness assessment of HbA1c routine assays: are processed EQA materials up to the job?
Fiche publication
Date publication
mai 2019
Journal
Clinical chemistry and laboratory medicine
Auteurs
Membres identifiés du Cancéropôle Est :
Pr GILLERY Philippe
Tous les auteurs :
Delatour V, Clouet-Foraison N, Jaisson S, Kaiser P, Gillery P
Lien Pubmed
Résumé
Background With the worldwide increase of diabetes mellitus prevalence, ensuring that HbA1c assays are accurate is essential. External quality assessment (EQA) programs enable laboratories to verify that analytical methods perform according to the manufacturers' specifications. However, assessing trueness requires commutable materials, a property that is rarely characterized for EQA materials. Methods The difference in bias approach was used to assess commutability of 26 processed quality control materials for 17 of the most frequently used HbA1c assays. Involved assays included immuno-assays, enzymatic assays, affinity, ion-exchange HPLC boronate affinity HPLC and capillary electrophoresis. The measurements were performed at manufacturers or expert laboratories. Assay trueness was additionally assessed against the IFCC reference measurement procedure using fresh clinical specimens that were distributed to 450 medical laboratories. Results Commutability of processed EQA materials was highly heterogeneous and globally insufficient to rigorously assess the trueness of HbA1c assays. Using fresh clinical specimens, mean bias was -0.13 mmol/mol for low HbA1c (34 mmol/mol), between +1.0 and +1.3 mmol/mol for intermediate HbA1c (49 and 58 mmol/mol) and +1.2 mmol/mol for elevated HbA1c (90 mmol/mol). Conclusions This study demonstrates that due to insufficient commutability, most processed EQA materials are unsuitable to assess trueness of HbA1c assays and agreement between the different assays. These materials can only provide information on comparability of individual laboratory results with its peers and on assay precision. Using fresh whole blood samples, this study additionally shows that most HbA1c assays are fairly accurate and meet the total allowable error quality target of 5 mmol/mol.
Mots clés
HbA1c, accuracy, accuracy-based program, commutability, comparability, external quality assessment schemes, glycated hemoglobin
Référence
Clin. Chem. Lab. Med.. 2019 May 14;: