Table 1 Demographic data and clinical characteristics of the study subjects
| Â | Non-AS | AS | Â |
|---|---|---|---|
(n = 309,110) | (n = 30,911) | P value | |
Age, years (mean ± SD) | 42 ± 17 | 42 ± 17 | 1.00 |
Sex | Â | Â | 1.00 |
 Female | 114,560 (37.1) | 11,456 (37.1) |  |
 Male | 194,550 (62.9) | 19,455 (62.9) |  |
CCI (mean ± SD) | 0.22 ± 0.74 | 0.35 ± 0.89 | < 0.01 |
CCI group |  |  | < 0.01 |
 0 | 269,864 (87.3) | 24,208 (78.3) |  |
 ≥ 1 | 39,246 (12.7) | 6703 (21.7) |  |
Prior IMID | |||
 Acute anterior uveitis | 604 (0.194) | 1695 (5.483) | < 0.01 |
 Psoriasis | 1019 (0.330) | 455 (1.472) | < 0.01 |
 Inflammatory bowel disease | 71 (0.023) | 18 (0.058) | < 0.01 |
 Crohn’s disease | 41 (0.013) | 7 (0.023) | 0.19 |
 Ulcerative colitis | 38 (0.012) | 13 (0.042) | < 0.01 |
 Systemic lupus erythematosus | 193 (0.062) | 79 (0.256) | < 0.01 |
 Sjögren’s syndrome | 137 (0.044) | 99 (0.320) | < 0.01 |
 Rheumatoid arthritis | 401 (0.13) | 345 (1.116) | < 0.01 |
 Systemic sclerosis | 20 (0.006) | 10 (0.032) | < 0.01 |
 Dermatomyositis | 12 (0.004) | 7 (0.023) | < 0.01 |
 Polymyositis | 11 (0.004) | 1 (0.003) | 0.93 |
 Thromboangiitis obliterans | 1 (0.0003) | 1 (0.003) | < 0.01 |
 Behcet’s disease | 18 (0.006) | 24 (0.078) | < 0.01 |
 Pemphigus | 16 (0.005) | 2 (0.006) | 0.77 |
 Sarcoidosis | 13 (0.004) | 6 (0.019) | < 0.01 |
 Vitiligo | 144 (0.047) | 30 (0.097) | < 0.01 |