Table 1. Odds ratios (ORs) (95% confidence intervals, CIs) of breast cancer associated with bisphosphonate use.
| Cases (N=2936) | Controls (N=2975) | Age adjusted | Multivariable adjusted | |
|---|---|---|---|---|
| Bisphosphonate use | N (%) | N (%) | OR (95% CI)a | OR (95% CI)b |
| Never use | 2808 (95.6) | 2788 (93.7) | 1.00 (Referent) | 1.00 (Referent) |
| Ever use | 128 (4.4) | 187 (6.2) | 0.70 (0.56–0.89) | 0.70 (0.54–0.92) |
| Former | 22 (0.7) | 26 (0.9) | 0.85 (0.48–1.51) | 0.91 (0.50–1.64) |
| Current | 106 (3.6) | 161 (5.4) | 0.68 (0.53–0.88) | 0.67 (0.51–0.89) |
| Duration of use (months) | ||||
| 3–12 | 58 (2.0) | 76 (2.5) | 0.78 (0.55–1.11) | 0.78 (0.54–1.12) |
| 13–24 | 26 (0.9) | 37 (1.2) | 0.72 (0.44–1.20) | 0.69 (0.41–1.17) |
| ⩾25 | 44 (1.5) | 74 (2.5) | 0.61 (0.42–0.90) | 0.63 (0.42–0.95) |
| P-trend | 0.01 | 0.01 | ||
a
Adjusted for age at diagnosis.
b
Additionally adjusted for parity, age at first live birth, family history of breast cancer, body mass index, menopausal status, age at menopause, type of hormone use, mammography, osteoporosis, smoking history, and height change.