Table 2.

SARS-CoV-2 antibody screening assay performance evaluation in healthy blood donors.

Assay		Negative	Grey zone	Positive	Sensitivity % [+/− 95% CI]	Specificity % [+/− 95% CI]	AUC [+/− 95% CI]	PPV % [+/− 95% CI]	NPV % [+/− 95% CI]
Abbott SARS-CoV-2 IgG		8051	341	117
	aw/o Grey zone	8051	–	117	75.6 [67.0 to 82.9]	99.7 [99.6 to 99.8]	0.877 [0.869 to 0.884]	79.5 [72.0 to 85.4]	99.6 [99.5 to 99.7]
	bGrey zone negative	8392	–	117	55.7 [47.8 to 63.4]	99.7 [99.6 to 99.8]	0.777 [0.768 to 0.786]	79.5 [71.8 to 85.5]	99.1 [99.0 to 99.3]
	cGrey zone positive	8051	–	458	75.6 [67.0 to 82.9]	95.7 [95.2 to 96.1]	0.856 [0.849 to 0.864]	20.3 [18.1 to 22.7]	99.6 [99.5 to 99.7]
Abbott SARS-CoV-2 IgGII Quant		8303	N/A	206	98.8 [95.7 to 99.9]	99.5 [99.3 to 99.6]	0.992 [0.989 to 0.993]	80.1 [74.8 to 84.5]	100.0 [99.9 to 100.0]
Abbott SARS-CoV-2 Total Ab		8315	N/A	194	96.8 [93.1 to 98.8]	99.8 [99.7 to 99.9]	0.983 [0.980 to 0.986]	93.3 [89.0 to 96.0]	99.9 [99.8 to 100.0]
Final ‘True’ Result		8322	N/A	187	–	–	–	–	–

^aGrey zone results were excluded from assay performance calculations.

^bGrey zone results were classified as negative for assay performance calculations.

^cGrey zone results were classified as positive for assay performance calculations.