Table 4. Hazard ratios of risk associated with baseline characteristics in univariate Cox's regression analysis.

Variables	VH
	HR	95%CI	P
Age (a)
<40	1.00
40-59	9.39	(8.64, 10.21)	<0.001
≥60	11.39	(10.39, 12.49)	<0.001
Sex
F	1.00
M	1.07	(1.01, 1.13)	0.03
Urbanization
1	1.00
2	1.01	(0.94, 1.09)	0.41
3	1.06	(0.99, 1.14)	0.11
Anti-coagulation drug
No	1.00
Yes	2.20	(2.07, 2.33)	<0.001

Urbanization level: 1 indicates the highest level of urbanization and 3 the lowest.