Table 2.

2 × 2 contingency table for all participants

		Leak (determined by quantitative fit test)
		QnFT fail (leak present)		n	QnFT pass (leak absent)		n	Row total
Bedside screening test (fogging)	Positive (fogging present)	True-positive	a =	25	False-positive (Type I error)	c =	19	a + c = 44
	Negative (fogging absent)	False-negative (Type II error)	b =	10	True-negative	d =	16	b + d = 26
	Column total		a + b =	35		c + d =	35

Formulas: Sensitivity = a/(a + c), specificity = d/(c + d), positive likelihood ratio = sensitivity/(1 − specificity), negative likelihood ratio = (1 − sensitivity)/specificity