Table 1.

Clinical performance of Roche Elecsys SARS-CoV-2 Antigen fully automated electrochemiluminescence immunoassay (ECLIA) stratified according to cycle threshold (Ct) values.

Ct values	AUC	Sensitivity	Specificity
All samples	0.83 (95%CI, 0.77–0.89; p < 0.001	0.43 (95%CI, 0.333–0.525)	1.00 (95%CI, 0.93–1.00)
<30	0.99 (95%CI, 0.98–1.00; p < 0.0001)	0.87 (95%CI, 0.75–0.945)	0.99 (95%CI, 0.95–1.00)
<25	1.00 (95%CI, 0.99–1.00; p < 0.001)	1.00 (95%CI, 0.89–1.00)	0.89 (95%CI, 0.82–0.94)

AUC, area under the curve; Ct, cycle threshold.