| Clinical features | Men (n = 40) | Women (n = 33) | p-values |
| Middle age | 30 ± 12.8 | 34.82 ± 11.62 | 0.124 |
| Family history (n = 35) | 21 (60%) | 14 (40%) | 0.391 |
| Ethnic group | 40 (54.8%) | 33 (45.2%) | 0.031 |
| Lumbar injury | 37 (54.4%) | 31 (45.6%) | 0.676 |
| Buttock pain | 38 (60.3%) | 25 (39.7%) | 0.017 |
| Peripheral involvement | 9 (50.0%) | 50 (50.0%) | 0.226 |
| History of uveitis (n = 35) | 10 (47.6%) | 11 (52.4%) | 0.434 |
| HLAB27 antigen (n = 42) | 20 (66.67%) | 10 (33.3%) | 0.200 |
| BASFI | 3.95 ± 0.81 | 3.89 ± 1.03 | 0.475 |
| BASDAI | 4.71 ± 1.34 | 4.5 ± 1.25 | 0.651 |