Characteristic | Unilateral study | Bilateral study | ||||||||
Unilateral oophorectomy (n=570) | Referent women (n=570) | p Value* | Bilateral oophorectomy (n=1653) | Referent women (n=1653) | p Value* | |||||
n | % | n | % | n | % | n | % | |||
Age at surgery | –† | –† | ||||||||
<30 | 97 | 17.0 | 97 | 17.0 | 30 | 1.8 | 30 | 1.8 | ||
30–34 | 103 | 18.1 | 103 | 18.1 | 103 | 6.2 | 103 | 6.2 | ||
35–39 | 143 | 25.1 | 143 | 25.1 | 211 | 12.8 | 211 | 12.8 | ||
40–45 | 166 | 29.1 | 166 | 29.1 | 687 | 41.6 | 687 | 41.6 | ||
46–49 | 61 | 10.7 | 61 | 10.7 | 622 | 37.6 | 622 | 37.6 | ||
Calendar year of surgery | –† | –† | ||||||||
1988–1992 | 138 | 24.2 | 138 | 24.2 | 317 | 19.2 | 317 | 19.2 | ||
1993–1997 | 109 | 19.1 | 109 | 19.1 | 406 | 24.6 | 406 | 24.6 | ||
1998–2002 | 147 | 25.8 | 147 | 25.8 | 553 | 33.5 | 553 | 33.5 | ||
2003–2007 | 176 | 30.9 | 176 | 30.9 | 377 | 22.8 | 377 | 22.8 | ||
Years of education‡ | 0.27 | <0.001 | ||||||||
<9 | 14 | 2.5 | 16 | 2.8 | 8 | 0.5 | 31 | 1.9 | ||
9–12 | 170 | 30.2 | 151 | 26.8 | 518 | 31.4 | 447 | 27.6 | ||
13–16 | 313 | 55.7 | 311 | 55.2 | 895 | 54.2 | 861 | 53.2 | ||
>16 | 65 | 11.6 | 85 | 15.1 | 229 | 13.9 | 279 | 17.2 | ||
Race | 0.54 | <0.001 | ||||||||
White | 538 | 94.4 | 535 | 93.9 | 1611 | 97.5 | 1570 | 95.0 | ||
Black | 15 | 2.6 | 16 | 2.8 | 18 | 1.1 | 29 | 1.8 | ||
Asian | 12 | 2.1 | 17 | 3.0 | 18 | 1.1 | 49 | 3.0 | ||
Other | 5 | 0.9 | 2 | 0.4 | 6 | 0.4 | 5 | 0.3 | ||
Hispanic ethnicity | 1.00 | 0.65 | ||||||||
No | 557 | 97.7 | 557 | 97.7 | 1633 | 98.8 | 1630 | 98.6 | ||
Yes | 13 | 2.3 | 13 | 2.3 | 20 | 1.2 | 23 | 1.4 |
*The p values were calculated using Χ2 tests or Fisher’s exact tests.
†Not applicable because of the matching by age and calendar year.
‡A total of 53 women had unknown education (8 unilateral oophorectomy, 7 unilateral referent, 3 bilateral oophorectomy and 35 bilateral referent) and were not included in the percentages.