Table 1 Age-standardized baseline characteristics according to current aspirin use
From: Aspirin use and risk of breast cancer in African American women
| Â | Current aspirin use | |
|---|---|---|
No (n = 47,591) | Yes (n = 5535) | |
Age, years* | 37.8 (10.2) | 43.9 (11.7) |
Current BMI, kg/m2 | 27.7 (6.6) | 29.1 (7.2) |
First-degree family history of breast cancer | 9 | 9 |
Postmenopausal, % | 16 | 18 |
Age at menarche | ||
 < 11 years, % | 11 | 13 |
 11 years, % | 17 | 16 |
 12–13 years, % | 52 | 50 |
 ≥ 14 years, % | 19 | 21 |
Recency of oral contraceptive use | ||
 Never, % | 23 | 26 |
 < 5 years ago, % | 28 | 24 |
 5–10 years ago, % | 11 | 11 |
 ≥ 10 years ago, % | 38 | 39 |
Postmenopausal hormone use | ||
 Never used estrogen plus progestin (E+P), % | 96 | 96 |
 Used E+P, < 5 years duration, % | 3 | 3 |
 Used E+P, ≥ 5 years duration, % | 1 | 1 |
Parity | ||
 Nulliparous, % | 36 | 33 |
 Parous, 1 birth, % | 21 | 20 |
 Parous, 2 births, % | 23 | 22 |
 Parous, ≥ 3 births, % | 19 | 23 |
Age at first birth (among parous) | ||
 < 20 years, % | 33 | 41 |
 20–25 years, % | 35 | 35 |
 ≥ 25 years, % | 30 | 21 |
Ever lactation (among parous), % | 52 | 48 |
Alcohol consumption | ||
 Not current drinker, % | 71 | 60 |
 Current, 1–6 drinks/week, % | 22 | 29 |
 Current, ≥ 7 drinks/week, % | 6 | 10 |
Educational attainment | ||
 ≤ 12 years, % | 17 | 27 |
 13–15 years, % | 36 | 39 |
 ≥ 16 years, % | 47 | 33 |