Diagnostic accuracy of tests for Helicobacter pylori in an Alaska Native population

Table 1 Characteristics of 280 patients enrolled in Anchorage, Alaska undergoing esophagogastroduodenoscopy during 1999 and 2000

Characteristic	% (n)
Mean age (min, max)	48 yr (19, 88)
Sex (female)	66% (184)
Medical chart review
History of peptic ulcer disease	19% (53)
Previous EGD	32% (90)
Previously treated for H. pylori	23% (63)
Endoscopist evaluation during EGD
Moderate-severe gastritis	41% (115)
Mild-no gastritis	59% (165)
Ulcer	9% (25)

EGD: Esophagogastroduodenoscopy; H. pylori: Helicobacter pylori.

Table 2 Percent positive for Helicobacter pylori by test type among 280 patients enrolled in Anchorage, Alaska for an Helicobacter pylori reinfection study, 1999-2000

Test type		% H. pyloripositive (n/N)
Histology	Antrum	49% (135/278)
	Fundus	46% (124/271)
	Combined	50% (140/280)
Culture	Antrum	48% (133/275)
	Fundus	50% (136/273)
	Combined	51% (144/280)
CLO test®1		49% (138/280)
Gold standard2		53% (149/280)
13C-UBT3		55% (155/280)
Anti-HP IgG	Indeterminates considered negative	60% (168/280)
	Indeterminates considered positive	67% (188/280)
	Indeterminates removed	65% (168/260)

¹Rapid urease test, Ballard Medical Products.

²A positive culture or in the case of a negative culture, a positive histology result and a positive campylobacter-like organism (CLO) test^®.

¹³C urea breath test (UBT)³, BreathTek^TM, Meretek Diagnostics Inc. H. pylori: Helicobacter pylori; Anti-HP IgG: Antibodies to H. pylori immunoglobulin G.

Table 3 Sensitivity and specificity of non-invasive tests in relation to invasive tests and a gold standard in 280 patients from Anchorage, Alaska, 1999-2000¹

Test type 1	Test type 2	Sensitivity	Specificity	NPV2	PPV2	Accuracy
13C-UBT3vs	Histology	93.6% (131/140)	82.9% (116/140)	92.8% (116/125)	84.5% (131/155)	88.2% (247/280)
	Histology and CLO test®4	96.8% (121/125)	78.1% (121/155)	96.8% (121/125)	78.1% (121/155)	86.4% (242/280)
	Culture	93.1% (134/144)	84.6% (115/136)	92.0% (115/125)	86.5% (134/155)	89.0% (249/280)
	Culture and CLO test®	94.6% (123/130)	78.7% (118/150)	94.4% (118/125)	79.4% (123/155)	86.1% (241/280)
	Gold standard	93.3% (139/149)	87.8% (115/131)	92.0% (115/125)	89.7% (139/155)	90.7% (254/280)
Anti-HP IgG vs	Histology	91.5% (118/129)	61.8% (81/131)	88.0% (81/92)	70.2% (118/168)	76.5% (199/260)
	Histology and CLO test®	93.1% (108/116)	58.3% (84/144)	91.3% (84/92)	64.3% (108/168)	73.8% (192/260)
	Culture	93.3% (126/135)	66.4% (83/125)	90.2% (83/92)	75.0% (126/168)	80.3% (209/260)
	Culture and CLO test®	93.4% (113/121)	60.4% (84/139)	91.3% (84/92)	67.3% (113/168)	75.8% (197/260)
	Gold standard	92.9% (130/140)	68.3% (82/120)	89.1% (82/92)	77.4% (130/168)	81.5% (212/260)
Anti-HP IgG vs	13C-UBT	91.0% (131/144)	68.1% (79/116)	85.9% (79//92)	78.0% (131/168)	80.8% (210/260)
Histology vs	Culture	87.5% (126/144)	89.7% (122/136)	87.1% (122/140)	90.0% (126/140)	88.6% (248/280)
CLO test®vs	Histology	89.3% (125/140)	90.7% (127/140)	89.4% (127/142)	90.6% (125/138)	90.1% (252/280)
CLO test®vs	Culture	90.3% (130/144)	94.1% (128/136)	90.1% (128/142)	94.2% (130/138)	92.1% (258/280)

¹The gold standard was a positive Helicobacter pylori (H. pylori) test by culture or, in the case of a negative culture result, a positive histology result and a positive campylobacter-like organism (CLO) test.

²Negative and positive predictive value (NPV and PPV).

¹³C urea breath test (UBT)³, BreathTek^TM, Meretek Diagnostics Inc. ⁴Rapid urease test, Ballard Medical Products. Anti-HP IgG: Antibodies to H. pylori immunoglobulin G.

Table 4 Among Helicobacter pylori positive persons (according to the gold standard, n = 149), the relationship between antibodies to Helicobacter pylori immunoglobulin G optical density and delta over baseline for the ¹³C urea breath test and demographics, histology and endoscopy outcomes

Factors	Anti-HP IgG OD1			13C-UBT DOB2
	High, OD≥1.1, (n = 76)	Low, OD < 1.1, (n = 73)	P value	High,≥10%, (n = 71)	Low, < 10%, (n = 78)	P value
Demographics
% Male	54% (41)	19% (14)	< 0.0001	31% (22)	42% (33)	0.15
% ≥ 50 years of age	33% (25)	40% (29)	0.39	53% (27)	29% (27)	0.002
Factors from histological examination
% Intestinal metaplasia	11% (8)	12% (9)	0.73	8% (6)	14% (11)	0.27
% Acute gastritis	55% (42)	49% (36)	0.47	49% (35)	55% (43)	0.48
% Chronic gastritis	93% (71)	77% (56)	0.003	86% (61)	85% (66)	0.82
% Numerous H. pylori	42% (32)	36% (26)	0.42	54% (38)	26% (20)	0.0005
Endoscopic factors
% Ulcer	10% (7)	11% (8)	0.76	9% (6)	12% (9)	0.57
% Gastritis	58% (42)	40% (29)	0.03	49% (34)	48% (37)	0.88

¹Antibodies to Helicobacter pylori (H. pylori) immunoglobulin G optical density (anti-HP IgG OD) was associated with male gender [P < 0.0001, odds ratio (OR) = 6.2] and chronic gastritis (P = 0.003, OR = 5.8) on multivariate analysis.

²Delta over baseline (DOB) from ¹³C urea breath test (UBT) test was associated with numerous H. pylori (P = 0.0005, OR = 3.6) and older age (P = 0.01, OR = 2.5) on multivariate analysis.