应用参考方法对血清γ-谷氨酰基转移酶的测量不确定度评定

Apply Reference Procedure to Evaluate the Measurement Uncertainty of Serum Gamma-glutamyltransferase

目的 探讨临床实验室对测量不确定度的评定方法和程序.方法 应用国际临床化学联合会（IFCC）公布的参考方法对参考实验室外部质量评价计划（RELA）样本进行γ-谷氨酰基转移酶（GGT）催化活性浓度测定,明确反映整个过程测量不确定度分量的来源,按A,B两类不确定度的计算方式对各分量分别进行评定,计算合成标准不确定度,最后取95%置信区间,计算出扩展不确定度.结果 GGT催化活性浓度均值为3.492 μkat/L,合成标准不确定度为0.032 μkat/L,取95%置信区间,包含因子k=2,则扩展不确定度（U）为0.064 μkat/L.结论 临床实验室的测量不确定度与传统的测量误差相比,更能反映测量的水平,对临床检验工作有一定的指导意义.

Objective To explore the method and procedure for evaluation of measurement uncertainty in clinical laboratory. Methods The concentration of gamma-glutamyltransferase （γ-GT,GGT） of the sample of external quality assessment program for reference laboratories （RELA） was measured by the reference procedure of IFCC;the sources of each uncertainty component in whole procedure of analysis were identified ;evaluation of the uncertainty components was processed by using two types of method and then a combined standard uncertainty was calculated, finally an expanded uncertainty was given according to 95% confidence interval. Results The average catalytic activity concentration of GGT was 3. 492μtkat/L,the related combined standard uncertainty was 0. 032 μkat/L,the 95% confidence interval was taken,the coverage factor （k） was 2,so the expanded uncertainty was 0. 064 μkat/L. Conclusion Compared with the traditional measurement errors, the measurement uncertainty in clinical laboratory could reflect the measurement ability and have instructive significance for routine clinical laboratory.