. 2011 May;84(1001):418–426. doi: 10.1259/bjr/20854868

Table 4. Specificity for the diagnosis of acute appendicitis (i.e. correctly diagnosing absence of appendicitis) per reader for positive vs neutral oral contrast.

	Specificity (%)^a	Specificity (%)^a	p-Value^b
	Positive oral contrast (Gastrografin) (n=99 cases without appendicitis)	Neutral oral contrast (VoLumen) (n=102 cases without appendicitis)	p-Value^b
Reader 1	97 (91–99)	95 (89–98)	0.7
Reader 2	98 (93–99)	93 (86–97)	0.17
Reader 3	97 (91–99)	90 (83–95)	0.08
Reader 4	92 (85–96)	95 (89–98)	0.4
Reader 5	95 (89–98)	97 (92–99)	0.5
Average of readers	(n=495) 96 (94–97)	(n=510) 94 (92–96)	0.24 (χ²)

^aBinomial exact 95% confidence intervals used for confidence interval reporting. ^bFisher's exact test.