TABLE 1.

Sensitivity and specificity values at various arbitrarily chosen cut off points for various tests^a

IgG parameter	Cutoff point for IgG		Test performance
	Level in serum	Avidity	% Sensitivity	(95% CI)	% Specificity	(95% CI)
Level in serum	7.6		18	(2-34)	100
	5.8		36	(16-56)	96	(88-100)
	4.5		55	(34-76)	92	(81-100)
Avidity		2.2	36	(16-56)	100
		1.9	45	(24-66)	96	(88-100)
		1.8	50	(29-71)	92	(81-100)
Level in serum plus avidity	7.6	2.2	45	(24-66)	100
	5.8	2.2	59	(38-80)	96	(88-100)
	4.5	2.2	68	(49-87)	92	(81-100)

^aIgG level in serum is the ELISA A₄₅₀; CI, confidence interval.