Abstract：
The goal of metrological traceability is to have equivalent results for a measurand in clinical samples (CSs) irrespective of the in-vitro diagnostic medical device (IVD-MD) used for measurements. The International Standards Organization standard 17511 defines requirements for establishing metrological traceability of values assigned to calibrators, trueness control materials and human samples used with IVD-MDs. Each step in metrological traceability has an uncertainty associated with the value assigned to a material. The uncertainty at each step adds to the uncertainty from preceding steps such that the combined uncertainty gets larger at each step. The combined uncertainty for a CS result must fulfil an analytical performance specification (APS) for the maximum allowable uncertainty (umax CS). The umax CS can be partitioned among the steps in a metrological traceability calibration hierarachy to derive the APS for maximum allowable uncertainty at each step. Similarly, the criterion for maximum acceptable noncommutability bias can be derived from the umax CS. One of the challenges in determining if umax CS is fulfilled is determining the repeatability uncertainty (u Rw) from operating an IVD-MD within a clinical laboratory. Most of the current recommendations for estimating u Rw from internal quality control data do not use a sufficiently representative time interval to capture all relevant sources of variability in measurement results. Consequently, underestimation of u Rw is common and may compromise assessment of how well current IVD-MDs and their supporting calibration hierarchies meet the needs of clinical care providers.
摘要：
计量可追溯性的目标是，无论用于测量的体外诊断医疗设备（IVD-MD）如何，在临床样本（CS）中对被测对象具有等效结果。国际标准化组织标准17511定义了建立分配给校准器的值的计量可追溯性的要求，与IVD-MD一起使用的真实性控制材料和人体样品。计量可追溯性的每个步骤都具有与分配给材料的值相关联的不确定性。每个步骤处的不确定性增加了来自先前步骤的不确定性,使得组合的不确定性在每个步骤处变得更大。CS结果的组合不确定性必须满足最大允许不确定性（umaxCS）的分析性能规范（APS）。可以在计量可追溯性校准等级中的步骤之间划分umaxCS，以得出每个步骤的最大允许不确定性的APS。同样，最大可接受的不可交换性偏差的标准可以从umaxCS中得出。确定是否满足umaxCS的挑战之一是确定在临床实验室内操作IVD-MD的可重复性不确定性（uRw）。从内部质量控制数据估计uRw的大多数当前建议都没有使用足够具有代表性的时间间隔来捕获测量结果中所有相关的变异性来源。因此,对uRw的低估是常见的,并且可能影响对当前IVD-MD及其支持的校准层级满足临床护理提供者需求的程度的评估。
