Table 1. General characteristics of exposure and control groups (%).

Variable	Exposure	Control	Total	χ2	P
Gender
Male	137 (76.1)	54 (47.0)	191 (64.7)	26.130	< 0.001
Female	43 (23.9)	61 (53.0)	104 (35.3)
Age(years)
≤ 40	53 (29.4)	67 (58.3)	120 (40.7)	24.146	< 0.001
> 40	127 (70.6)	48 (41.7)	175 (59.3)
Smoking
Yes	63 (35.0)	12 (10.4)	75 (25.4)	22.333	< 0.001
No	117 (65.0)	103 (89.6)	220 (74.6)
Drinking
Yes	16 (8.9)	30 (26.1)	46 (15.6)	15.769	< 0.001
No	164 (91.1)	85 (73.9)	249 (84.4)