Table 3. Correlation between IUD use and breast cancer risk.
| Premenopausal women | Postmenopausal women | |||||||
| Case N (%) |
Control N (%) |
cORd (95% CI) |
aORe (95% CI) |
Case N (%) |
Control N (%) |
cORd (95% CI) |
aORf (95% CI) |
|
| IUD usea | ||||||||
| Never | 165 (36.8) | 199 (43.0) | 1 | 1 | 131 (37.9) | 131 (38.3) | 1 | 1 |
| Ever | 283 (63.2) | 264 (57.0) | 1.29 (0.99–1.69) | 1.17 (0.88–1.55) | 215 (62.1) | 211 (61.7) | 1.02 (0.75–1.39) | 1.23 (0.88–1.71) |
| Total time of IUD use, yearsb | ||||||||
| 0 | 165 (36.8) | 199 (43.0) | 1 | 1 | 131 (37.9) | 131 (38.3) | 1 | 1 |
| 0.1–5.0 | 43 (9.6) | 18 (3.9) | 2.88 (1.60–5.19) | 3.05 (1.64–5.67) | 33 (9.5) | 18 (5.3) | 1.83 (0.98–3.42) | 1.81 (0.92–3.54) |
| 5.1–10.0 | 53 (11.8) | 34 (7.3) | 1.88 (1.17–3.03) | 2.04 (1.23–3.37) | 20 (5.8) | 13 (3.8) | 1.54 (0.74–3.22) | 2.03 (0.89–4.62) |
| 10.1–15.0 | 49 (10.9) | 42 (9.1) | 1.41 (0.89–2.23) | 1.43 (0.87–2.34) | 31 (9.0) | 36 (10.5) | 0.86 (0.50–1.47) | 0.96 (0.53–1.74) |
| 15.1–20.0 | 79 (17.6) | 61 (13.2) | 1.56 (1.06–2.31) | 1.58 (1.02–2.43) | 55 (15.9) | 31 (9.1) | 1.77 (1.07–2.93) | 1.97 (1.14–3.38) |
| >20.0 | 59 (13.2) | 109 (23.5) | 0.65 (0.45–0.95) | 0.43 (0.27–0.67) | 76 (22.0) | 113 (33.0) | 0.67 (0.46–0.98) | 0.72 (0.47–3.38) |
| Ptrendc | 1.07 (0.302) | 2.27 (0.132) | ||||||
aA total of 1,599 subjects.
bA total of 1,599 subjects who had never used IUD or had complete information on total time of IUD use.
cIt is a P value estimated by test of linear by linear Chi square test.
dcOR: crude OR, it is an OR value estimated by unconditional logistic regression with non-confounders adjusted.
eaOR: adjusted OR, it is an OR value estimated by multivariate logistic regression with age, per capita annual income, history of active smoking, passive smoking and amount of physical activity adjusted.
faOR: adjusted OR, it is an OR value estimated by multivariate logistic regression with age, per capita annual income, history of active smoking, alcohol drinking and history of live birth adjusted.