Basic characteristics of 466 subjects (296 cases, 170 controls). Numbers do not add up to the total number of cases because some test results were not recorded.
| Characteristics | Cases | Controls |
|---|---|---|
| Sex (men/women) | 228/68 | 128/42 |
| Average age, yrs, SD | 29.19 ± 9.86 | 24.66 ± 6.66 |
| No. patients juvenile onset/adult onset | 114/170 | |
| B-27 (negative/positive) | 14/155 | |
| Kyphosis (negative/positive) | 169/120 | |
| Bamboo spine (negative/positive) | 195/94 | |
| Radiographic grading of sacroiliitis (2/3–4) | 123/167 |