Table 1.

Demographic characteristics of participants in the case–control study.

	Case (n = 442)	Control (n = 428)	Statistics	p value
Regions			0.298	0.998
West Lake District	209	209
Lin’an	51	49
Jiashan	41	37
Qujiang	83	77
Wenling	39	37
Pujiang	19	19
Age	52.23 ± 15.27	50.53 ± 15.03	1.652	0.968
Gender			3.382	0.066
Male	285(64.48%)	250 (58.41%)
Female	157 (35.52%)	178 (41.59%)
Educational level			4.519	0.104
Elementary level or below	144 (32.58%)	112 (26.17%)
Junior or senior high school	209 (47.29%)	227 (53.04%)
University or higher	89 (20.14%)	89 (20.79%)