Table 1.
Baseline characteristics of the women in the Multiethnic Cohort, by hysterectomy status
| Characteristic | No simple hysterectomya | Simple hysterectomy | pb | ||
|---|---|---|---|---|---|
| n | (%) | n | (%) | ||
| Age (years) | |||||
| < 60 | 30327 | (54.9) | 6004 | (47.0) | |
| ≥ 60 | 24953 | (45.1) | 6781 | (53.0) | <0.0001 |
| Ethnicity | |||||
| White | 14289 | (25.8) | 3207 | (25.1) | |
| African American | 8604 | (15.6) | 3570 | (27.9) | |
| Native Hawaiian | 4233 | (7.7) | 830 | (6.5) | |
| Japanese American | 16912 | (30.6) | 2331 | (18.2) | |
| Latina - US born | 5692 | (10.3) | 1774 | (13.9) | |
| Latina - not US born | 5550 | (10.0) | 1073 | (8.4) | <0.0001 |
| Age at menopause or hysterectomy (years) | |||||
| Premenopausal | 13248 | (24.0) | - | ||
| < 45 | 6620 | (12.0) | 9761 | (76.3) | |
| 45-49 | 13312 | (24.1) | 2202 | (17.2) | |
| ≥ 50 | 22100 | (40.0) | 822 | (6.4) | - |
| Age at menarche (years) | |||||
| ≤ 12 | 26948 | (48.7) | 6798 | (53.2) | |
| 13-14 | 21561 | (39.0) | 4680 | (36.6) | |
| ≥ 15 | 6771 | (12.2) | 1307 | (10.2) | <0.0001 |
| Age at first birth (years) | |||||
| Never | 7193 | (13.0) | 1306 | (10.2) | |
| ≤ 20 | 14193 | (25.7) | 5021 | (39.3) | |
| 21-30 | 29434 | (53.2) | 6027 | (47.1) | |
| ≥ 30 | 4460 | (8.1) | 431 | (3.4) | <0.0001 |
| Number of children | |||||
| 0 | 7193 | (13.0) | 1306 | (10.2) | |
| 1 | 6272 | (11.3) | 1299 | (10.2) | |
| 2-3 | 25141 | (45.5) | 5512 | (43.1) | |
| ≥ 4 | 16674 | (30.2) | 4668 | (36.5) | <0.0001 |
| BMI (kg/m2) | |||||
| < 25 | 29490 | (53.3) | 5569 | (43.6) | |
| 25-< 30 | 16012 | (29.0) | 4306 | (33.7) | |
| ≥ 30 | 9778 | (17.7) | 2910 | (22.8) | <0.0001 |
| Current estrogen and progestin use | |||||
| No | 45701 | (82.7) | 12478 | (97.6) | |
| Yes | 9579 | (17.3) | 307 | (2.4) | <0.0001 |
| Current estrogen use | |||||
| No | 52807 | (95.5) | 8369 | (65.5) | |
| Yes | 2473 | (4.5) | 4416 | (34.5) | <0.0001 |
| Past estrogen and progestin use | |||||
| No | 51497 | (93.2) | 11831 | (92.5) | |
| Yes | 3783 | (6.8) | 954 | (7.5) | <0.0001 |
| Alcohol intake (drinks/day) | |||||
| Never | 41869 | (75.7) | 9734 | (76.1) | |
| < 1 | 8275 | (15.0) | 1922 | (15.0) | |
| 1-< 2 | 2678 | (4.8) | 629 | (4.9) | |
| ≥ 2 | 2458 | (4.4) | 500 | (3.9) | 0.0003 |
| Education (years) | |||||
| ≤ 12 | 23357 | (42.3) | 5957 | (46.6) | |
| > 12 | 31923 | (57.7) | 6828 | (53.4) | <0.0001 |
| Family historyc | |||||
| No | 49452 | (89.5) | 11244 | (87.9) | |
| Yes | 5828 | (10.5) | 1541 | (12.1) | 0.0006 |
| Previous mammography | |||||
| Never | 7153 | (12.9) | 1044 | (8.2) | |
| > 2 years ago | 6020 | (10.9) | 1347 | (10.5) | |
| Within 2 years | 42107 | (76.2) | 10394 | (81.3) | <0.0001 |
a
Premenopausal women and postmenopausal women who had natural menopause
b
p-value from logistic regression adjusted for age (continuous) and ethnicity. Age is adjusted for ethnicity only and ethnicity is adjusted for age only
c
Family history of breast cancer in mother or a sister