Fig. 1. Distribution of QCs shown in Table 3 as a function of their placement within the quartiles of the calibration range, indicating a preference for QCs to be placed in the lower quartile of the measurement interval. The two QCs with reported concentrations above the AMR were within 15% of the upper limit of quantification.
Abbreviations: QC, quality control; AMR, analytical measurement range.

Ann Lab Med 2022;42:121~140 https://doi.org/10.3343/alm.2022.42.2.121