Table 3. Multivariate analysis of risk factors associated with Helicobacter pylori reinfection.

Risk factors	Pa	HR	95% CI
			Lower	Upper
Geo-location of residence
Northern China	Reference
Central China	<0.001	4.9	3.0	8.1
Northeastern China	0.052	1.9	1.0	3.8
Southern China	0.64	0.6	0.1	4.6
Western China	<0.001	5.5	2.6	11.5
Eastern China	0.578	1.9	0.2	19.0
Ethnicity
Han	0.005	5	1.6	10
Minority
Education level
Above	Reference
Secondary education	0.444	0.7	0.3	1.7
Below	0.027	1.7	1.1	2.6
A family history of gastric cancer
With	<0.001	9.9	6.6	14.7
Without

^aCox regression model.