Table 2.

Best-case scenario: validity of chickenpox history, grouping together negative, equivocal and insufficient IgG.

	VZV IgG Result				Total
	Positive		Negative, equivocal or insufficient
	n	% [95% CI]	n	% [95% CI]	n
Chickenpox history
Positive	109	90.8% [85.6–96.0%]	11	9.1% [4.0–14.4%]	120
Negative	52	67.5% [57.0–78.1%]	25	32.5% [21.2–43.0%]	77
Uncertain	42	84.0% [73.7–94.3%]	8	16.0% [5.7–26.3%]	50
Negative or uncertain	94	74.0% [66.3–81.7%]	33	26.0% [18.3–33.7%]	127

p-Values for comparison of proportions were calculated as follows: positive vs. negative: p < 0.001; positive vs. negative or uncertain: p < 0.001; positive vs. uncertain: p = 0.284; negative vs. uncertain: p = 0.041.