Table 1 Sample description
Variable | Category | Cases (%) | Controls (%) | p |
|---|---|---|---|---|
Age at recruitment | < 45 years | 214 (19) | 234 (18) | < 0.001 |
45–54 years | 317 (28) | 282 (21) | ||
55–64 years | 296 (26) | 290 (22) | ||
65–74 years | 180 (16) | 313 (24) | ||
≥ 75 years | 132 (12) | 203 (15) | ||
Educational level | Unfinished primary | 162 (14) | 246 (19) | 0.02 |
Primary studies | 391 (34) | 405 (31) | ||
Secondarystudies | 366 (32) | 405 (31) | ||
High education | 220 (19) | 266 (20) | ||
Parity | Nulliparous | 254 (22) | 242 (18) | 0.007 |
1 | 207 (18) | 200 (15) | ||
2 | 445 (39) | 516 (39) | ||
≥ 3 | 233 (21) | 364 (28) | ||
Age at menarche | ≤ 12 years | 436 (38) | 487 (37) | 0.46 |
> 12 years | 703 (62) | 835 (63) | ||
Menopausal status | Premenopausal | 657 (59) | 889 (67) | < 0.001 |
Postmenopausal | 464 (41) | 433 (33) | ||
Age at menopause | < 50 years | 329 (47) | 445 (50) | 0.18 |
≥ 50 years | 378 (53) | 447 (50) | ||
Age at first delivery | < 20 years | 70 (8) | 70 (7) | 0.50 |
20–24 years | 247 (28) | 286 (28) | ||
25–29 years | 329 (37) | 410 (40) | ||
30–34 years | 163 (19) | 187 (18) | ||
≥ 35 years | 69 (8) | 64 (6) | ||
Tobacco use | Non- smoker | 607 (53) | 792 (60) | 0.001 |
Former smoker | 304 (27) | 274 (21) | ||
Current smoker | 228 (20) | 256 (19) | ||
Body Mass Index (kg/m2) | < 18.5 | 15 (1) | 26 (2) | 0.34 |
18.5–24.9 | 527 (46) | 638 (48) | ||
25.0–29.9 | 387 (34) | 414 (31) | ||
≥ 30.0 | 210 (18) | 244 (18) | ||
Family history of breast cancer | No | 764 (67) | 1097 (83) | < 0.001 |
First-degree relative | 167 (14) | 121 (9) | ||
Second-degree relative | 24 (2) | 14 (1) | ||
Other relative | 178 (16) | 89 (7) | ||
Hormonal contraceptive | No | 628 (55) | 725 (55) | 0.88 |
Yes | 511 (45) | 597 (45) | ||
Hormone replacement therapy | No | 1021 (90) | 1177 (89) | 0.70 |
Yes | 83 (7) | 100 (8) |