临床化学定量检测项目室间质量评价靶值不确定度的建立与应用

Establishment and Application of the Uncertainty of Target Value in External Quality Assessment for Quantitative Testing in Clinical Chemistry

目的 探讨临床化学定量检测项目室间质量评价（external quality assessment,EQA）靶值不确定度的建立方法及应用.方法 收集2012年第2次临床化学室间质量评价所有参加实验室1 549家的5个质评物原始检测结果,包括钾、钠、氯、钙、磷、葡萄糖、尿素、尿酸、肌酐、总蛋白、清蛋白、胆固醇、三酰甘油、总胆红素、丙氨酸氨基转移酶、天门冬氨酸氨基转移酶、碱性磷酸酶、肌酸激酶、乳酸脱氢酶和γ-谷氨酰基转移酶共20个检验项目.各项目按照检测方法分组,参考ISO 13528稳健算法A,计算各分组稳健均值及稳健标准差.将稳健均值作为各分组靶值,用稳健标准差计算靶值标准不确定度（ux）,判断是否满足：ux≤0.3（能力评定标准差）.收集实验室A血清葡萄糖检测项目2012年5月室内质控长期累积在控变异系数和2012年第2,3次室间质量评价10个批号质评物的血清葡萄糖检测结果,通过自上而下方法,结合靶值标准不确定度,计算该实验室血清葡萄糖的测量不确定度.结果 大部分检测项目的 靶值不确定度满足要求,不满足要求的靶值需在EQA结果解释时使用靶值不确定度.实验室A的血清葡萄糖相对测量不确定度为16.1%.结论 参考ISO 13528建立的靶值及其标准不确定度方法适用于我国室间质量评价计划,可填补室间质量评价靶值不确定度领域的空白,提高实验室性能评价的科学性和可靠性,并为医学实验室评定测量不确定度提供更直接的数据来源.

Objective To discuss the establishment of the uncertainty of target value in External Quality Assessment（EQA） for quantitative testing in clinical chemistry and its application in evaluation of the measurement uncertainty in medical labo-ratory. Methods Collected the raw data of biochemistry testing for 5 control materials in 2nd EQA,2012. Laboratories with same measurement method were classified as one group. Referred to Algorithm A,a robust method described in ISO 13528, to calculate the target value and its standard uncertainty for each control material. The standard uncertainty was then judged whether met the criterion., ux≤0. 3σ,where a means the standard deviation for proficiency evaluation. Took Glucose as an ex-ample to explain how the standard uncertainty of the target value was applied in the evaluation of the measurement uncer-tainty in medical laboratory. Results The standard uncertainty of the most target values could meet the criterion,except for 4 analytes,whose standard uncertainty should be included in the result evaluation. The relative measurement uncertainty of glucose was 16.1 % for laboratory A. Conclusion The approach for establishment of target value and its standard uncertain-ty described in ISO 13528 is appropriate for EQA in China. Furthermore,it is the first time the uncertainty of the target val-ue has been provided,which can improve the reliability of EQA and provide a necessary and direct data resource for calcula-tion of the measurement uncertainty in medical laboratories.