HbA1c measurement in Germany: Is the quality sufficient for follow-up and diagnosis?

Measurement of the HbA(1c) value represents an essential laboratory measure for the follow-up and therapy decision in patients with diabetes. High demands on the measurement quality of the measured variable can already be derived from the use of the HbA1c value for them. The use for diagnostic purposes requires even more for the monitoring explicit high analytical accuracy and precision. The HbA(1c) is one of the parameters in laboratory medicine that can be evaluated according to the guidelines of the German Medical Association (Rili-BAEK) in external quality control using the reference method value. The allowed deviation of +/- 18 % in external quality assessment (EQA) schemes and +/- 10 % in internal quality control has been ultimately met by virtually all the different manufacturers and methods. However, these broad limits for permissible deviations and the previously frequent/common use of EQA scheme materials that are not equally suitable for all systems, resulted in the fact that in HbA(1c) analytics inaccurately measured values or incorrectly calibrated devices are difficult to identify in Germany. With the implementation of unprocessed fresh EDTA blood, the situation has changed. This inter-laboratory material resembles patient blood as possible. Artificial matrix effects are thereby largely avoided. In the interests of high transparency, the POCT systems for HbA1c measurement in Germany should also participate in EQA scheme and all data should be made public. There is also the objective of aligning the requirements for quality criteria with international standards. This position paper out-lines the need to narrow the acceptance limits for HbA(1c) 's internal (to +/- 3 %) and external (to +/- 8 %) quality controls in Rili-BAEK. Higher quality in HbA(1c) measurements should avoid misdiagnosis of diabetes as well as potentially wrong and partially dangerous therapeutic consequences. What is technically feasible and market considerations must not play a role against medical requirements. In this context, an improvement in the communication of all participants by establishing a "Round Table HbA(1c)" is encouraged. Similarly, the involvement of the International and European medical associations in the field of diabetology (ADA/EASD) and clinical chemistry (IFCC) in the topic of HbA(1c) measurement should be strengthened.