Table 4.

Agreement between the COVID-19 IgG/IgM Duo and Elecsys anti-SARS-CoV-2 assay depending on the onset of symptoms

Overall			Elecsys anti-SARS-CoV-2
			Pos		Neg		Total
COVID-19 IgG-IgM Duo (IgM or IgG)	Pos		30 (29%)		15 (14%)		45
	Neg		0 (0%)		60 (57%)		60
	Total		30		75		105
% overall agreement: 85.7% % positive percent agreement: 100.0% % negative percent agreement: 80.0% Kappa value (95% CI): 0.696 (0.560–0.831)
0–6 days			Elecsys anti-SARS-CoV-2
			Pos		Neg		Total
COVID-19 IgG-IgM Duo (IgM or IgG)	Pos		2 (5%)		7 (19%)		9
	Neg		0 (0%)		28 (76%)		28
	Total		2		35		37
% overall agreement: 81.1% % positive percent agreement: 100.0% % negative percent agreement: 80.0% Kappa value (95% CI): 0.302 (−0.032–0.635)
7–13 days				Elecsys anti-SARS-CoV-2
				Pos		Neg		Total
COVID-19 IgG-IgM Duo (IgM or IgG)		Pos		24 (43%)		9 (16%)		33
		neg		0 (0%)		23 (41%)		23
		total		24		32		56
% overall agreement: 83.9% % positive percent agreement: 100.0% % negative percent agreement: 71.9% Kappa value (95% CI): 0.687 (0.508–0.865)
≥14 days				Elecsys anti-SARS-CoV-2
				Pos		Neg		Total
VID-19 IgG-IgM Duo (IgM or IgG)		pos		34 (57%)		5 (8%)		39
		neg		0 (0%)		21 (35%)		21
		total		34		26		60
% overall agreement: 91.7% % positive percent agreement: 100% % negative percent agreement: 80.8% Kappa value (95% CI): 0.826 (0.683–0.970)