Table 1.
Characteristic | Cases (n = 415) | Controls (n = 629) | P Valuea | ||||
---|---|---|---|---|---|---|---|
No. of Participants | % | Mean (SD) | No. of Participants | % | Mean (SD) | ||
Age group, yearsb | |||||||
20–39 | 19 | 4.6 | 71 | 11.3 | <0.001 | ||
40–49 | 69 | 16.6 | 105 | 16.7 | |||
50–59 | 150 | 36.1 | 237 | 37.7 | |||
60–69 | 114 | 27.5 | 160 | 25.4 | |||
70–79 | 63 | 15.2 | 56 | 8.9 | |||
State of residenceb | |||||||
Michigan or Illinois | 40 | 9.6 | 93 | 14.8 | 0.03 | ||
Ohio | 31 | 7.5 | 60 | 9.5 | |||
New Jersey | 36 | 8.7 | 49 | 7.8 | |||
North Carolina | 67 | 16.1 | 100 | 15.9 | |||
South Carolina | 56 | 13.5 | 51 | 8.1 | |||
Georgia | 73 | 17.6 | 130 | 20.7 | |||
Tennessee or Alabama | 45 | 10.8 | 64 | 10.2 | |||
Louisiana | 32 | 7.7 | 44 | 7.0 | |||
Texas | 35 | 8.4 | 38 | 6.0 | |||
Education | |||||||
High school or less | 180 | 44.3 | 232 | 36.9 | 0.05 | ||
Some post-high school training | 131 | 32.3 | 229 | 36.4 | |||
College or graduate degree | 95 | 23.4 | 168 | 26.7 | |||
Parity | |||||||
0 | 81 | 19.5 | 83 | 13.2 | 0.02 | ||
1–2 | 179 | 43.1 | 283 | 44.9 | |||
>2 | 155 | 37.4 | 263 | 42.0 | |||
Oral contraceptive use | |||||||
Never | 120 | 28.9 | 123 | 19.6 | 0.002 | ||
<60 months | 167 | 40.2 | 284 | 45.2 | |||
≥60 months | 128 | 30.8 | 222 | 35.3 | |||
Postmenopausal | 304 | 73.3 | 436 | 69.3 | 0.17 | ||
Ever use of hormone replacement therapyc | 79 | 26.3 | 100 | 23.0 | 0.32 | ||
Tubal ligation | 139 | 33.5 | 256 | 40.7 | 0.02 | ||
Family history of breast/ovarian cancer (first-degree relative) | |||||||
No | 297 | 73.2 | 494 | 78.5 | 0.007 | ||
Yes | 109 | 26.9 | 115 | 18.3 | |||
Unknown | 9 | 2.2 | 20 | 3.2 | |||
Body mass indexd | 33.3 (9.0) | 32.2 (8.2) | 0.03 | ||||
Total energy intake, kcal | 1,783.3 (1,214.4) | 1,744.5 (1,127.8) | 0.60 | ||||
Healthy Eating Index–2005, score | 61.0 (10.3) | 60.9 (10.7) | 0.93 | ||||
Healthy Eating Index–2010, score | 61.0 (11.1) | 61.7 (11.2) | 0.34 | ||||
Alternate Healthy Eating Index–2010, score | 51.7 (10.3) | 53.1 (11.1) | 0.04 |
Abbreviation: SD, standard deviation.
a Student's t test for continuous variables and χ2 tests for categorical variables.
b This study was designed to frequency match controls to cases by 5-year age category and state of residence. The differences in age and state of residence between cases and controls may, in part, be because this is an ongoing study that is still enrolling participants.
c Restricted to postmenopausal women.
d Body mass index was calculated as weight (kg)/height (m)2, from measurements 1 year before diagnosis (cases) or reference date (controls).