Table 2.

Overall prevalence of Helicobacter pylori infection

Parameter	Prevalence, % (n/total)	P value
Total	33.1 (7416/22421)
Sex		0.771
Male	33.1 (6014/18158)
Female	32.9 (1402/4263)
Age group in year		< 0.001
18-29	33.9 (2137/6301)
30-39	34.9 (3080/8818)
40-49	31.8 (1108/3487)
50-59	29.6 (664/2244)
60-69	26.2 (298/1138)
70-79	29.8 (129/433)
Hospital location		< 0.001
Beijing	29.0 (1929/6659)
Chengdu	37.9 (397/1048)
Guangzhou	32.3 (435/1348)
Lanzhou	44.3 (1671/3771)
Nanjing	31.1 (2984/9595)