Wood William Graham, Hanke Rainer, Meissner Dieane, Reinauer Hans
Reference Method Laboratories, Instand e. V., Düsseldorf, Germany.
Clin Lab. 2003;49(3-4):151-9.
This article describes the preparation and internal and external evaluation of materials, critical issues in the external quality assessment (EQA) of point-of-care testing (POCT) devices for measuring blood glucose. A comparison was made between different materials, both of natural and synthetic origin and with and without stabilisers. The aims were to produce a material which was compatible with as many POCT-devices as possible and so reduce the number of materials sent out in each campaign as well as to optimise the precision and comparability of results between methods and devices. Although the use of near natural material--sterile-filtered plasma spiked with glucose--survived internal testing, this material proved to be unsuitable for EQA surveys. The study resulted in the reduction of materials for each survey to stabilised whole blood for one device, stabilised plasma for two devices and a synthetic material based on a polyethylene glycol matrix for all other devices. Samples were sent as pairs six times annually. The POCT-devices tested measured precisely but inaccurately in the synthetic material, when compared with the reference method (gas-chromatography coupled with isotope-dilution mass-spectrometry; GC-IDMS), so that the devices could only be evaluated for precision. The construction of ratios between the concentrations measured on the two samples distributed allowed an indirect assessment of accuracy. The need for surveillance of POCT devices is stressed in this publication, which combines theory and practice in setting up and running an EQA programme for blood glucose.
本文介绍了用于测量血糖的即时检测（POCT）设备的外部质量评估（EQA）中材料的制备、内部和外部评估。对不同材料进行了比较，这些材料既有天然来源的，也有合成来源的，有加稳定剂的和未加稳定剂的。目的是生产一种与尽可能多的POCT设备兼容的材料，从而减少每次活动中发出的材料数量，并优化不同方法和设备之间结果的精密度和可比性。尽管使用接近天然的材料——添加葡萄糖的无菌过滤血浆——通过了内部测试，但这种材料被证明不适用于EQA调查。该研究结果是每次调查的材料减少为一种设备使用稳定化全血、两种设备使用稳定化血浆以及所有其他设备使用基于聚乙二醇基质的合成材料。样本每年分六次成对发送。与参考方法（气相色谱-同位素稀释质谱联用；GC-IDMS）相比，所测试的POCT设备在合成材料中测量精确但不准确，因此这些设备只能评估精密度。通过构建在分发的两个样本上测量的浓度之间的比率，可以间接评估准确性。本出版物强调了对POCT设备进行监测的必要性，它在建立和运行血糖EQA计划方面将理论与实践相结合。
