Table. 1. Table 1

Results of MU estimation using different calculation methods

Analytes	QC level 1			QC level 2			No. of reagent lots used

	U_{rel_tot} (%)	U_{rel_sub} (%)	%Difference^*	U_{rel_tot} (%)	U_{rel_sub} (%)	%Difference
Albumin	2.944	2.881	0.063	2.565	2.479	0.086	3
ALP	4.259	4.013	0.245	4.085	3.59	0.495	3
ALT	8.01	7.995	0.015	2.591	2.573	0.018	2
AST	5.425	5.382	0.043	2.939	2.908	0.031	3
HDL	4.655	4.165	0.49	5.348	4.523	0.825	3
LDL	4.414	4.312	0.101	3.926	3.837	0.089	2
Total cholesterol	3.554	3.491	0.064	3.567	3.485	0.083	4
Creatinine	5.847	5.813	0.034	4.345	4.334	0.011	3
Glucose	2.159	2.085	0.073	2.144	2.068	0.076	4
Total protein	2.359	2.311	0.048	2.29	2.263	0.028	4
Triglyceride	2.581	2.579	0.002	2.534	2.532	0.002	3
K	1.538	1.538	7.13E-05	1.284	1.282	0.002	2
Na	1.557	1.525	0.032	1.368	1.347	0.021	4
BUN	4.366	4.306	0.06	3.477	3.458	0.02	4
Mean	4.752	4.606	0.146	3.575	3.342	0.232	2.9
Median	4.414	4.165	0.064	3.567	3.485	0.086	3
Min (analyte)	2.944	2.881	1.45E-02	2.534	2.532	0.018	2
		K			Triglyceride
Max (analyte)	4.655	4.165	0.49	5.348	4.523	0.825	4
		HDL			HDL

*%Difference = % U_{rel_tot} – %Sub U_{rel_sub}

Abbreviations: MU, measurement uncertainty; QC, quality control; U_{rel_tot}, expanded relative uncertainty (coverage factor, k=2) calculated regardless of reagent lot change, akin to CV; U_{rel_sub}, expanded relative uncertainty (coverage factor, k=2) with obtained values from each subgroup, akin to CV; ALP, alkaline phosphatase; K, potassium; Na, sodium; BUN, blood urea nitrogen.

Ann Lab Med 2022;42:630~637 https://doi.org/10.3343/alm.2022.42.6.630