Table 1. Baseline characteristics in women with and without hysterectomy.

	Hysterectomy	Comparison group
	(n = 9 189)	(n = 33 942)	SMD
Age, years
30–39	1285 (13.98)	5063 (14.92)	0.03
40–49	5692 (61.94)	20795 (61.27)	0.01
50–59	1481 (16.12)	5348 (15.76)	0.01
≧60	731 (7.96)	2736 (8.06)	0.004
median (Q1-Q3)	45.45 (42.22–49.78)	44.24 (41.42–49.77)	0.03
Urbanization
1	3066 (33.37)	11972 (35.27)	0.04
2	2797 (30.44)	10158 (29.93)	0.01
3	1518 (16.52)	5532 (16.3)	0.01
4	1808 (19.68)	6280 (18.5)	0.03
Insurance premium
0~15000	2067 (22.49)	8293 (24.43)	0.05
15000~30000	5434 (59.14)	19181 (56.51)	0.05
≧30000	1688 (18.37)	6468 (19.06)	0.02
Occupation
White collar	4853 (52.81)	19442 (57.28)	0.08
Blue collar	3715 (40.43)	12146 (35.78)	0.09
Other	621 (6.76)	2354 (6.94)	0.09
Oophorectomy	965 (10.50)	1046 (3.08)	0.30
Charlson comorbidity index
0	8323 (90.58)	31913 (94.02)	0.13
1	355 (3.86)	1039 (3.06)	0.04
≧2	511 (5.56)	990 (2.92)	0.13
Estrogen treatment
Estradiol and premarin	38 (0.41)	59 (0.17)	0.04
Follow up times, year
median (Q1-Q3)	6.66 (3.78–10.14)	7.32 (4.26–10.67)	0.12

SMD: Standard mean difference.