Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Department of Laboratory Medicine, Konkuk University School of Medicine, Seoul, Korea.
Ann Lab Med. 2022 Nov 1;42(6):630-637. doi: 10.3343/alm.2022.42.6.630.
The top-down (TD) approach using internal quality control (IQC) data is regarded a practical method for estimating measurement uncertainty (MU) in clinical laboratories. We estimated the MU of 14 clinical chemistry analytes using the TD approach and evaluated the effect of lot changes on the MU.
MU values were estimated using subgrouping by reagent lot changes or using the data as a whole, and both methods were compared. Reagent lot change was simulated using randomly generated data, and the mean values and MU for two IQC datasets (different QC material lots) were compared using statistical methods.
All MU values calculated using subgrouping were lower than the total values; however, the average differences were minimal. The simulation showed that the greater the increase in the extent of the average shift, the larger the difference in MU. In IQC data comparison, the mean values and MU exhibited statistically significant differences for most analytes. The MU calculation methods gave rise to minimal differences, suggesting that IQC data in clinical laboratories show no significant shift. However, the simulation results demonstrated that notable differences in the MU can arise from significant variations in IQC results before and after a reagent lot change. Additionally, IQC material lots should be treated separately when IQC data are collected for MU estimation.
Lot changes in IQC data are a key factor affecting MU estimation and should not be overlooked during MU estimation.
使用内部质量控制（IQC）数据的自上而下（TD）方法被认为是临床实验室估计测量不确定度（MU）的实用方法。我们使用 TD 方法估计了 14 个临床化学分析物的 MU，并评估了批变化对 MU 的影响。
使用试剂批变化的分组或使用整个数据来估计 MU 值，并比较这两种方法。使用随机生成的数据模拟试剂批变化，并使用统计方法比较两个 IQC 数据集（不同 QC 材料批次）的平均值和 MU。
使用分组计算的所有 MU 值均低于总数值，但平均差异最小。模拟结果表明，平均偏移量增加的幅度越大，MU 的差异就越大。在 IQC 数据比较中，大多数分析物的平均值和 MU 存在统计学差异。MU 计算方法的差异很小，表明临床实验室的 IQC 数据没有明显的偏移。然而，模拟结果表明，在试剂批变化前后 IQC 结果的显著变化可能会导致 MU 的显著差异。此外，在收集 MU 估计的 IQC 数据时，应分别处理 IQC 材料批次。
IQC 数据的批变化是影响 MU 估计的关键因素，在 MU 估计过程中不应忽视。
