Status of analytical and post-analytical harmonization in the measurement of glycated hemoglobin HbA1c

Overview

Objective: Description of state for harmonization of HbA_1c in blood measurement using two big international comparison studies.

Materials and methods: We used the results for % HbA_1c results obtained in study NGSP-CAP and for mmol/mol results obtained by study EurA1c. We are assessed precision and bias values, influence of different APS values on the postanalytical interpretation results and possibility for derivation of APS from biological variability.

Results and discussion: Comparability of results between different methods, EQA programs and countries remains significant number of laboratories with unsuitable low level of precision and bias. Very probably due to using some IVD kits lower quality. Significant differences in precision are observed due to use of using two different measurement units. Quality of analytical technology is not on the desirable level for personalized approach. An impossibility using APS values derived from biological variation is consequence of this fact. APS values suggested by experts (6% for NGSP units and 8% for IFCC units) are in this moment optimal and may serve as good basis for harmonization, external quality control and also for application of artificial intelligence and machine learning in near future. Using the commutable reference materials are absolute condition.

Keywords:

HbA1c – APS – measurement units – NGSP – EurA1c – precision and bias