Likelihood of having peripheral arthritis, enthesitis, inflammatory back pain or active disease at year 4 depending on status at study entry
| Status at study entry | Status after 4 years* |
|---|---|
| Peripheral arthritis present | |
| Peripheral arthritis present (n=82) | 29% (17%; 44%) |
| No peripheral arthritis (n=26) | 8% (4%; 18%) |
| Enthesitis present | |
| Enthesitis present (n=18) | 8% (2%; 32%) |
| No enthesitis (n=88) | 3% (1%; 12%) |
| IBP present | |
| IBP present (n=23) | 53% (31%; 74%) |
| No IBP (n=94) | 5% (3%; 15%) |
| Active disease present | |
| All patients | 54% (41%; 66%) |
| HLA-B27 positive (n=73) | 59% (45%; 72%) |
| HLA-B27 negative (n=37) | 42% (26%; 59%) |
| Male (n=79) | 50% (37%; 63%) |
| Female (n=31) | 63% (44%; 79%) |
| Positive SpA family history (n=57) | 39% (25%; 56%) |
| No SpA family history (n=41) | 66% (50%; 80%) |
*Likelihood of a certain disease status is expressed in per cent; 95% confidence limits are shown in parentheses.