Evaluation of dot immunogold filtration assay for anti-HAV IgM antibody

Table 1 Comparison of DIGFA results with ELISA

		ELISA		Total
		+	-
DIGFA	+	a	b	a+b
	-	c	d	c+d
Total		a+c	b+d	N

Table 2 Formulae for evaluation of DIGFA

Index	Formulae	Index	Formulae
Sensitivity	a/(a+c)	Specificity	d/(b+d)
Positive predictive value	a/(a+b)	Negative predictive value	d/(c+d)
Accuracy	(a+d)/N	Youden index	[a/(a+c)]/[d/(b+d-1)]
Positive likelihood ratio	[a/(a+c)]/[b/(b+d)]	Negative Likelihood ratio	[c/(a+c)]/[d/(b+d)]

Table 3 Comparison of DIGFA results with ELISA

		ELISA		Total
		+	-
DIGFA	+	88	16	104
	-	14	146	160
Total		102	162	264