Table 2.
Age-adjusted relative risk (RR) and absolute risk (AR), with 95% confidence intervals (95% CIs), of atypical femoral fracture associated with use of bisphosphonate in women and men 55 years of age or older, during the 3-year period 2008–2010
| Bisphosphonate use | No. of atypical fractures | Crude incidence n/10,000 patient-years | Age-adjusted RR (95% CI) | Age-adjusted AR (95% CI) |
|---|---|---|---|---|
| Women | ||||
| Never use | 30 | 0.08 | Reference | Reference |
| Any type of bisphosphonate | 130 | 5.0 | 55 (39–79) | 0.0005 (0.0004–0.0006) |
| Alendronate | 117 | 5.9 | 63 (41–97) | 0.0006 (0.0005–0.0007) |
| Risedronate | 15 | 5.4 | 35 (19–66) | 0.0003 (0.0001–0.0006) |
| Men | ||||
| Never use | 8 | 0.03 | Reference | Reference |
| Any type of bisphosphonate | 4 | 1.6 | 54 (15–192) | 0.0002 (0.0000–0.0003) |
| Women compared to men a | ||||
| Men, users of bisphosphonate | 4 | 1.6 | Reference | Reference |
| Women, users of bisphosphonate | 86 | 5.0 | 3.1 (1.1–8.4) | 0.0003 (0.0001–0.0005) |
| Men, non-users | 8 | 0.030 | Reference | Reference |
| Women, non-users | 21 | 0.072 | 2.3 (1.0–5.3) | < 0.000001 |
a
Based on data from 2009 and 2010.