Sempos Christopher T, Betz Joseph M, Camara Johanna E, Carter Graham D, Cavalier Etienne, Clarke Michael W, Dowling Kirsten G, Durazo-Arvizu Ramon A, Hoofnagle Andrew N, Liu Andy, Phinney Karen W, Sarafin Kurtis, Wise Stephen A, Coates Paul M
National Institutes of Health, Office of Dietary Supplements, Bethesda, MD.
National Institute of Standards and Technology, Chemical Sciences Division, Gaithersburg, MD.
J AOAC Int. 2017 Sep 1;100(5):1230-1233. doi: 10.5740/jaoacint.17-0259. Epub 2017 Aug 1.
The Vitamin D Standardization Program (VDSP) has collaborated with numerous groups and agencies to assemble a set of tools, i.e., a reference measurement system, that can be used to establish the traceability of 25-hydroxyvitamin D [25(OH)D] assays to relevant reference measurement procedures and reference materials. This is done with the goal of verifying end-user laboratory performance using precise statistical criteria to determine whether a specific assay is standardized. The purpose of this paper was to outline a set of steps that routine clinical and research laboratories can use to standardize their 25(OH)D assays using these tools. These steps apply to laboratories using commercially developed immunoassay measurement systems as well as in-house assays, usually based on high HPLC or LC tandem MS measurement systems. The steps are (1) initial calibration, (2) initial assessment of accuracy and bias, (3) assessment of total percent CV and mean bias, (4) use of trueness controls, and (5) participation in accuracy-based performance testing and/or external quality assessment schemes. The goal of each laboratory assay is to have a total CV of ≤10% and mean bias of ≤5%. Rigorous and less rigorous but low-cost options for meeting these statistical criteria are provided. Research laboratories who infrequently measure 25(OH)D are advised to repeat steps 1-4 for every measurement cycle. For users of commercial immunoassays who have relatively little control over standardization, we present an option for using trueness controls to develop a master equation that can be used to standardize results to the reference methods.
维生素D标准化计划（VDSP）已与众多团体和机构合作，组装了一套工具，即参考测量系统，可用于建立25-羟基维生素D[25(OH)D]检测相对于相关参考测量程序和参考物质的可追溯性。这样做的目的是使用精确的统计标准来验证最终用户实验室的性能，以确定特定检测是否标准化。本文的目的是概述一套常规临床和研究实验室可用于使用这些工具对其25(OH)D检测进行标准化的步骤。这些步骤适用于使用商业开发的免疫分析测量系统以及通常基于高效液相色谱或液相色谱串联质谱测量系统的内部检测的实验室。这些步骤包括：（1）初始校准；（2）准确性和偏差的初始评估；（3）总变异系数百分比和平均偏差的评估；（4）使用真实性对照；（5）参与基于准确性的性能测试和/或外部质量评估计划。每个实验室检测的目标是总变异系数≤10%，平均偏差≤5%。本文提供了满足这些统计标准的严格和不太严格但低成本的选项。建议不常测量25(OH)D的研究实验室在每个测量周期重复步骤1-4。对于对标准化控制相对较少的商业免疫分析用户，我们提出了一种使用真实性对照来开发主方程的选项，该方程可用于将结果标准化为参考方法。
