| Category | RA | RA | Non-RA | Non-RA | Rate Ratio |
|---|---|---|---|---|---|
| scans | Rate per 100 py | scans | Rate per 100 py | (95% CI) | |
| X-ray hand/wrist | 2908 | 39.8 | 650 | 8.6 | 4.62 (4.25, 5.04) |
| X-ray ankle/foot | 2237 | 30.6 | 809 | 10.7 | 2.86 (2.64, 3.10) |
| All Upper extremity* | 3843 | 52.7 | 1335 | 17.7 | 2.97 (2.80, 3.17) |
| All Lower Extremity* | 3808 | 52.2 | 1910 | 25.5 | 2.05 (1.94, 2.16) |
| All chest* | 6155 | 84.7 | 4777 | 63.5 | 1.33 (1.28,1.38) |
| DEXA | 843 | 11.5 | 490 | 6.5 | 1.77 (1.59, 1.98) |
| All radionuclide bone** | 183 | 2.5 | 99 | 1.3 | 1.90 (1.50, 2.44) |