Table 1.
Descriptive characteristics of the participants
| Variable | Cases | Controls | P-value | |
|---|---|---|---|---|
| N (%) | N (%) | |||
| Education | Elementary | 33 (11.6) | 40 (14.0) | 0.310* |
| Middle school | 42 (14.7) | 54 (18.9) | ||
| Diploma | 112 (39.3) | 95 (33.3) | ||
| University | 98 (34.4) | 96 (33.7) | ||
| Employment status | Employed | 53 (18.6) | 57 (20.0) | 0.880* |
| Not employed | 232 (81.4) | 228 (80.0) | ||
| Marital status | Married | 230 (80.7) | 240 (84.2) | 0.413* |
| Single | 37 (13.0) | 26 (9.1) | ||
| Widow or divorced | 18 (5.4) | 19 (6.7) | ||
| Gravida | 0 | 13 (5.2) | 18 (6.9) | 0.011* |
| 1 | 52 (21.0) | 35 (13.5) | ||
| 2 | 93 (37.5) | 90 (34.7) | ||
| 3≤ | 90 (36.3) | 116 (44.8) | ||
| Number of abortions | 0 | 165 (66.5) | 170 (65.6) | 0.854* |
| 1 | 59 (23.8) | 60 (23.2) | ||
| 2≤ | 24 (9.7) | 29 (11.2) | ||
| History of breastfeeding | Yes | 223 (78.2) | 229 (80.4) | 0.535* |
| No | 62 (21.8) | 56 (19.6) | ||
| Number of times breastfeed | 1 | 79 (35.4) | 52 (22.7) | 0.001* |
| 2 | 108 (48.4) | 109 (47.6) | ||
| 3 | 29 (13.0) | 57 (24.9) | ||
| 4≤ | 7 (3.1) | 11(4.8) | ||
| History of infertility | Yes | 26 (9.1) | 15 (5.3) | 0.750* |
| No | 259 (90.9) | 270 (94.7) | ||
| History of infertility treatment | Yes | 26 (9.1) | 13 (4.6) | 0.031* |
| No | 259 (90.9) | 272 (95.4) | ||
| Contraception method | Hormonal | 62 (21.8) | 59 (20.7) | 0.390* |
| Withdrawal | 105 (36.8) | 122 (42.8) | ||
| Non-hormonal | 54 (19.0) | 57 (20.0) | ||
| No method | 64 (22.5) | 47 (16.5) | ||
| Family history of breast cancer | Yes | 63 (22. 1) | 54 (18.9) | 0.351* |
| No | 222 (77.9) | 231 (81.1) | ||
| History of PCOS | Yes | 36 (12.6) | 12 (4.2) | < 0.001* |
| No | 249 (87.4) | 273 (95.8) | ||
| Mean ± SD | Mean ± SD | |||
| Age of the menarche (years) | 13.09 ± 1.47 | 13.33 ± 1.52 | 0.058** | |
| Age at the first pregnancy (years) | 23.53 ± 5.37 | 22.99 ± 4.77 | 0.247** | |
| Age at the first breastfeeding (years) | 23. 93 ± 5.49 | 23.34 ± 4.72 | 0.216** | |
| Total duration of breastfeeding (months) | 36.60 ± 20.56 | 39.93 ± 19.71 | 0.079** | |
| Total duration of infertility (years) | 8.88 ± 7.30 | 10.26 ± 7.63 | 0.569** | |
*. Comparisons were tested using the chi-square test
**. Comparisons were tested using the independent t-test