Helicobacter pylori infection causes gastric cancer A? review of the epidemiological, meta-analytic, and experimental evidence

Table 3 Summary of all meta-analyses looking at the association between H pylori and gastric cancer

StudyFactors	Huang et al 1998[16]	Danesh 1999[19]	Eslick et al 1999[18]	Xue et al 2001[93]	HCCG 2001[94]	Huang et al 2003[95]
Journal	Gastroenterology	Aliment Pharm Ther	Am J Gastroenterol	World J Gastroenterol	Gut	Gastroenterology
Number of studies	19	44	42	11	12	16
Cohort studies	5	10	8	0	0	0
Case-control studies	14	34	34	11	12	16
Peer-reviewed papers	18	37	42	†	12	12
Abstracts	1	7	0	†	0	4
Non-English language studies	English only	No restrictions	No restrictions	Chinese only	†	No restrictions
Searching method(s)	MEDLINE,	MEDLINE, Reference lists, hand searching	MEDLINE, Current contents, CINAHL, CANCER CD, Biological abstracts, manual searches, contact investigators	Chinese Biomedical database (CBM)	MEDLINE, contact investigators	MEDLINE, PubMed, contact investigators
	Conference proceedings (1994-1996), manual searches
Search terms used	Campylobacter pylori, stomach neoplasms, Helicobacter pylori	Campylobacter pylori, gastric adenocarcinoma, gastric cancer,	Campylobacter pyloridis, Campylobacter pylori, gastric carcinoma, gastric cancer, Helicobacter pylori	Helicobacter pylori, gastric carcinoma, gastric cancer, precancerous lesion of stomach	†	Helicobacter pylori, meta-analysis, stomach neoplasms
		Stomach cancer,
		Helicobacter pylori
Time period	1983-1996	1983-1998	1983-March 1999	1995-2001	1985-1999	1990-2003
H pylori status	Serology only	Serology only	Serology & histology	†	Serology	Serology
Statistical analysis	Random-effects M-H or D&L	Inverse-variance- weighted log risk odds	Random-effects D&L	Fixed-effects	Logistic regression	Random-effects D&L
Number of studies in analysis	19	10	42	11	12	16
Pooled oddas ratio (OR)	1.92	2.5	2.04	2.56	2.36	2.28
95% confidence interval (CI)	1.32-2.78	1.90-3.40	1.69-2.45	1.85-3.55	1.98-2.81	1.71-3.05
Overall (P-value) heterogeneity	0.2	> 0.05	0.001	> 0.05	0.09	< 0.001
Quality assessment	Yes	No	Yes	No	No	Yes
Assessment of publication bias	No	No	Yes	No	†	Yes
Duplicate studies	Removed	†	Removed	†	†	Removed
Number of reviewers	Two	One	Two	†	†	Three

† Not stated. D&L: DerSimonian & Laird ¹⁵. M-H: Mantel-Haenszel ¹⁶.