Table 2. Association of registration with gender, education and number of hospital visits in Jing'an district, Shanghai, China, 2010.

Variable	Odds ratio	95%CI	P
Sex			0.57
Female	1
Male	1.157	0.68-1.98
Education			0.01
Illiteracy or primary school education	1
Junior middle school or above education	2.59	1.49-4.48
Hospital visits (times)
<4	1
≥4	2.54	1.47-4.38	0.01 or 3