Helicobacter pylori infection and gastric cancer: evidence from a retrospective cohort study and nested case-control study in China

Table 1 The general information of the H. pylori positive and H. pylori negative cohorts

	H. pylori positive cohort	H. pylori negative cohort	Total	P
Gender(male/female)	1671(881/790)*	1048(520/528)	2719(1399/1320)	>0.05
Muping	675(424/251)	380(239/141)		= 1.000
Zhoushan	501(285/216)	370(183/187)		= 0.033*
Changzhou	495(172/323)	298(98/200)		= 0.643
Age ( < 50, 50-60, ≥ 60)	1671(604,505,562)	1048(366,310,372)	2719(970,815,934)	>0.05
Muping	675(216,189,270)	380(102,110,168)		0.082,0.096
Zhoushan	501(221,138,142)	370(142,109,119)		0.097,0.224
Changzhou	495(167,178,150)	298(112,91,85)		0.108,0.131
Economic Status(well,poor)	1612(1513,99)	1007(949,58)	2619(2462,157)	>0.05(0.719-0.734)
Smoking(yes, no)	1610(877,733)	1006(566,450)	2616(1433,1183)	>0.05(0.123-1.0)
Alcohol drinking(yes, no)	1610(624,986)	1006(384,622)	2616(1008,1608)	>0.05(0.07-0.814)
Family history of gastric cancer(yes, no)	1670(167,1503)	1046(98,948)	2716(265,2451)	>0.05(0.277-0.948)

*The number in the parenthesis indicated the relevant number of each category defined in the first column.

Table 2 Follow-up duration of the cohort

Fields	n	Average follow-up duration(yrs)	Standard devisiom
Muping	1055	11.1496	2.8798
Zhoushan	871	14.1883	2.5603
Changzhou	793	6.5596	2.1343
Total	2719	10.8805	4.0358

Table 3 The distribution of gastric cancer deaths observed in the follow-up period of the cohorts

Field	H. pylori positive cohort		H. pylori positive cohort		Total
	n	No. of gastric cancer death	n	No. of gastric cancer death	n	No. of gastric cancer death
Muping	675	9	380	3	1055	12
Zhoushan	501	10	370	6	871	16
Changzhou	495	14	298	2	793	16
Total	1671	33	1048	11	2719	44

Table 4 Result of logistic regression analysis of different age groups

Variables	OR	95%CI
< 50 years old	4.601	1.885,11.229
50-60 years old	1.916	0.961,3.822
≥ 60 years old	Do not convergence

Table 5 The results of Cox regression analysis with adjustment of age and sex

Variable	β	S.E	Wald	df	P	RR	95%CI
							lower	upper
H. pylori	0.6856	0.3485	3.8705	1	0.0491	1.9850	1.0026	3.9301
Age	0.9062	0.5005	3.2773	1	0.0702	2.4748	0.9278	6.6010
Sex	-0.3237	0.3203	1.0215	1	0.3122	0.7234	0.3861	1.3554

Table 6 The result of conditional logistic analysis of H. pylori and gastric cancer risk

	β	P	OR	95%CI (lower)	95%CI(upper)
H. pylori infection	1.497	0.0295	4.467	1.1610	17.1900
Non-farmer	-1.415	0.0669	0.243	0.0535	1.1040
Poor economic condition	1.287	0.2022	3.620	0.5011	26.1600
Usually drank unboiled water	1.099	0.1565	3.000	0.6564	13.710
Wash hands before meals	-1.896	0.0241	0.150	0.0289	0.7798
Like to eat smoked food	0.913	0.2102	2.492	0.5974	10.3900
Lower vegetables intake	0.5153	0.4542	1.674	0.4342	6.4550
Smoking	5.808	0.0037	332.800	6.5840	1.683e + 004
Older age started to smoke	-0.145	0.0137	0.865	0.7707	0.9707
Lower fruits intake	-0.524	0.4836	0.592	0.1367	2.5660
History of upper addominal pain	0.678	0.3027	1.970	0.5425	7.1530