New concept for control material in glucose point-of-care-testing for external quality assessment schemes.

Objectives: Until now, the external quality assessment (EQA) of glucose point-of-care testing (POCT) has lacked a high quality, suitable and commutable control material to assess measurement accuracy. Here we present a concept for determining the accuracy of glucose measurements, which uses human whole blood and does not require stabilising agents.

Methods: This new generation of quality control samples uses a bead that contains a specific amount of glucose. The bead is then dissolved in a whole blood matrix by the EQA participant immediately before the POCT. We analysed its suitability as an EQA material with respect to its reproducibility, homogeneity and stability, and applied it in an EQA pilot study. The glucose target value was determined using the reference measurement procedure and served as an evaluation criterion for the accuracy of the EQA survey results.

Results: The homogeneity and stability of the new control material fulfilled the quality requirements of ISO 17043. Based on the reference measurement value for glucose, the results of the pilot EQA scheme showed a pass rate of 84.6 % for the participating POCT devices. The acceptance limit was a 15 % permitted deviation from the target value according to Rili-BAEK. All of the device collectives deviated from the target value by 0-4.4 % with the exception of one device type, which deviated by 21 %.

Conclusions: The new concept offers, for the first-time, whole blood-based trueness controls for glucose POCT analysis for external quality assurance. The concept does not require the addition of any stabilising reagent and is easy to use.