Table 4 Incident rate ratio* for first fracture in the subjects with arthritis compared with healthy controls.
| Age category (years) | Female subjects | Male subjects | Combined† |
|---|---|---|---|
| <10 | 1.94 (0.96 to 3.48) | 1.17 (0.54 to 2.24) | 1.49 (0.91 to 2.31) |
| 10–15 | 3.71 (1.96 to 6.42) | 2.79 (1.80 to 4.15) | 3.13 (2.21 to 4.33) |
| 15–20 | 1.37 (0.50 to 3.02) | 1.89 (1.21 to 2.84) | 1.75 (1.18 to 2.51) |
| 20–45 | 1.57 (0.63 to 3.26) | 1.25 (0.74 to 1.98) | 1.40 (0.91 to 2.08) |
| >45 | 4.25 (2.07 to 7.89) | 3.15 (1.00 to 7.57) | 3.97 (2.23 to 6.59) |
| Test for heterogeneity | p = 0.05 | p = 0.04 | p<0.001 |
*IRR (95% confidence interval); †when models were stratified by sex and age category at the start of follow up, we did not identify effect modification between the diagnosis of arthritis and sex on the risk of fracture in any age category.