Transtympanic Electrocochleography for the Diagnosis of Ménière's Disease

Table 4

Formula for calculating the diagnostic power of the two subjective tests, respectively, as compared with the diagnosis based on ECochG measures.

		ECochG diagnosis
		(hypothetical “gold standard”)
		Positive	Negative
Results from AAO-HNS CHE (or Gibson score)	Positive	a; (true positive)	b; (false positive)
	Negative	c; (false negative)	d; (true negative)

Sensitivity = a/(a+c).
Specificity = d/(b+d).
Positive predictive value = a/(a+b).
Negative predictive value = d/(c+d).