Table 1.

Study Characteristics Of Reviewed Articles

No	Author	Study Design	Sample Size	Year	Country	Method	Result
1	Carrick J, Lee A, Hazell S, Ralston M, Daskalopoulos G	Cohort	137	1989	Australia	Congo Red staining	Strong risk factor (RR=51)21
2	Moss SF, Calam J	Randomized clinical trial	9	1993	England	Endoscopy and biopsies	Eradication reduce basal plasma gastrin concentration (P<0.05), and basal acid secretion (P<0.01)39
3	Reinbach DH, Cruickshank G, McColl KE	Matched hospital case control	80	1993	United Kingdom	Serum anti-H pylon IgG and ‘4C-urea breath tests	Prevalence 47%32
4	Batista SA, et al	Experimental	112	2011	Brazil	Endoscopy	Number of EPIYA C segments did not associate with duodenal ulcer41
5	Cekin AH, et al	Matched case control	222	2012	Turkey	Esophago-gastroduodenoscopy	H. pylori located in the corpus [OR]=3.00; incisura OR=2.07; and antrum [OR]=2.71. Hp positivity was 84.9%27
6	Gisbert JP, et al	Cross-sectional	774	1999	Spain	Endoscopy	Prevalence 95.3%34
7	Tsuji H, et al	Cross-sectional	120	1999	Japan	Endoscopic, rapid urease test and forceps biopsies	1.7% H. pylori-negative rates12
8	Gdalevich M, et al	Nested case control	29	2000	Israel	ELISA IgG-Ab	OR=3.831
9	Khan MM, Shahzed MN, Jibran M, Rabbani MJ	Cross-sectional	116	2009	Pakistan	ACON®	116 patients (92 males and 24 females) have perforated DU and more common in 30–50 age groups48
10	Lario S, et al	Cohort	88	2013	Spain	Microarrays	Higher levels of IL8 and IL12p40 mRNAs and lower levels of GATA6 and SOCS2 mRNAs49
11	Labenz JO, et al	Cross-sectional	16	1996	Germany	pH metry, glass electrode, urea breath test, culture, histology, and rapid urease	H. pylori eradication decrease the pH-increasing effect of omeprazole; P<0.00236
12	Olbe L, Hamlet A, Dalenback J, Fandriks L	Cross-sectional	16	1996	Sweden	Urea breath test, culture, histology, and rapid urease	Inhibitory mechanism was restituted in 8 of 10 patients within 9 months after eradication of H. pylori infection5
13	Chu KM, Kwok KF, Law S, Wong KH	Cross-sectional	1343	2005	China	Endoscopic, rapid urease test and biopsies	Male preponderance (M:F=2.5:1)13
14	Syam AF, et al	Cross-sectional	267	2014	Indonesia	Culture, histology and rapid urease test	Prevalence 22.1%10
15	Segal ED, Cha J, Lo J, Falkow S, Tompkins LS	Laboratory		1999	USA	ELISA IgG-Ab	145-kDa protein and activation of signal transduction pathways associated with the attachment of H. pylori19
16	Borody TJ, et al	Cohort	302	1991		Endoscopic, rapid urease test and biopsies	94% were found to have associated H pylori44
17	Ng EK, et al	Cohort	73	1996		Intra-operative gastroscopy and antral biopsies	70% had evidence of H. pylori33
18	Rauws EA, Tytgat GN	Randomized clinical trial	50	1990			Eradication achieved 7 of the 45 patients and there was no ulcer relapse during the first 12 months of follow-up38
19	Patchett S, Beattie S, Leen E, Keane C, O’Morain C	Cohort	51	1992		Endoscopic, biopsies	Recurrence of H. pylori infection occurred in 35.3%29
20	Chan FK	Randomized clinical trial	100	1997	Hong Kong	Endoscopy	Eradication of H pylori before NSAID therapy reduces the occurrence16
21	Blaser MJ, Chyou PH, Nomura A	Case control	313	1995	USA		H. pylori do not increases risk of developing duodenal ulcer40
22	Nomura A, Stemmermann GN, Chyou PH, Perez-Perez GI, Blaser MJ	Nested case control	5443	1994	USA	ELISA IgG-Ab	92% patients and 78% of the matched controls had a positive test result, OR=4.028
23	Kim JG, Graham DY	Cross-sectional	181	1994		ELISA IgG-Ab	36% developed a duodenal ulcer45
24	Borody TJ, Brandl S, Andrews P, Jankiewicz E, Ostapowicz N	Cross-sectional	115	1992	Australia	Endoscopy	47 (66%) no detectable causal factors, 21 (30%) regularly taking NSAIDs, and three (4%) had malignant GU17
25	Bytzer P, Teglbjærg PS, Group DU	Randomized clinical trial	276	2001		Culture, immunohistochemistry, and urea breath test	Eradication therapy over 2 years is significantly poorer in H. pylori-negative patients7
26	Escobar MA, et al	Cross-sectional	169	2004			12% of patients develop late complications26