Table 3. Agreement between qualitative results (positive or negative) and correlation between quantitative values of different tests in COVID-19 patients’ samples (n = 97).

Tests	Agreement between qualitative results, %
	Correlation between quantitative values, ρ (p<0.001 in all significant cases)
	Epitope	Euroimmun	Roche	Abbott	DiaSorin	LIPS S-RBD	LIPS N	Biosensor
SNIBE	85	77	85	86	80	84	76	85
	0.91	0.64	0.68	0.84	0.70	0.6	0.56	NAa
Epitope		82	90	93	84	91	86	77
		0.56	0.59	0.80	0.65	0.53	0.46	NAa
Euroimmun			87	81	95	88	85	74
			0.66	0.65	0.95	0.73	0.50	NAa
Roche				89	88	91	88	79
				0.78	0.71	0.67	0.51	NAa
Abbott					82	90	87	78
					0.71	0.59	0.51	NAa
DiaSorin						87	84	77
						0.78	0.53	NAa
LIPS S-RBD							80	76
							NSb	NAa
LIPS N								71
								NAa

^a NA–not applicable. Only qualitative interpretation (absence or presence of test line).

^bNS–no significant correlation (p>0.05).