Sensitivity is not an intrinsic property of a diagnostic test: empirical evidence from histological diagnosis of Helicobacter pylori infection

Table 1 Sensitivity of histological assessment of Helicobacter pylori infection using PCR analysis as the reference standard, in Portuguese and Mozambican populations of dyspeptic patients.

	Helicobacter pyloriinfection
	PCR (reference standard)	Histological assessment (index text)
	+	+	-	Sensitivity (95%CI)
All participants
Portugal	104	100*	4	96.2 (90.4-98.9)
Mozambique	95	63†	32	66.3 (55.9-75.7)
Participants not reporting previous eradication treatment
Portugal	97	95‡	2	97.9 (92.7-99.7)
Mozambique	62	41§	21	66.1 (53.0-77.7)
Participants not reporting previous PPI/H2 receptor blockers treatment
Portugal	75	74#	1	98.7 (92.8-100.0)
Mozambique	37	22¶	15	59.4 (42.1-75.2)
Excluding participants reporting previous eradication and PPI/H2 receptor blockers treatments
Portugal	97	95**	2	97.9 (92.7-99.7)
Mozambique	66	42††	24	63.6 (50.9-75.1)

PCR - Polymerase chain reaction; 95%CI - 95% confidence interval; PPI - Proton pump inhibitors * H. pylori density score: mild (5.0%); moderate (42.0%); marked (53.0%), † H. pylori density score: mild (20.6%); moderate (34.9%); marked (44.4%), ‡ H. pylori density score: mild (5.3%); moderate (42.1%); marked (52.6%), §H. pylori density score: mild (19.5%); moderate (43.9%); marked (36.6%), # H. pylori density score: mild (5.4%); moderate (44.6%); marked (50.0%), ¶H. pylori density score: mild (27.3%); moderate (40.9%); marked (31.8%), ** H. pylori density score: mild (5.3%); moderate (42.1%); marked (52.6%), †† H. pylori density score: mild (21.4%); moderate (42.9%); marked (35.7%)

ISSN: 1471-230X