Demographics and disease characteristics of the 202 patients of this study
| Number of patients | 202 |
| Age (years) | 38.2±12.6 |
| Gender (male) | 147 (72.8%) |
| HLA-B27 | 177 (88.9%) |
| Smoking status (current) | 35 (17.3%) |
| Smoking status (ever) | 39 (19.3%) |
| Alcohol | 27 (13.4%) |
| Disease duration (months) | 87.5±86.6 |
| Uric acid (umol/L) | 380.2±107.7 |
| BASDAI | 3.3±1.9 |
| ASDAS-CRP | 2.6±1.1 |
| BASFI (0–10) | 1.8±2.2 |
| Axial involvement (any) | 181 (89.6%) |
| Peripheral involvement (any) | 104 (51.5%) |
| Axial involvement (only) | 103 (51.0%) |
| Peripheral involvement (only) | 25 (12.4%) |
| Mixed (axial and peripheral involvement) | 84 (41.6%) |
| Enthesitis involvement | 25 (12.4%) |
| Dactylitis | 9 (4.5%) |
| Uveitis | 35 (17.3%) |
| Psoriasis | 10 (5.0%) |
| IBD | 4 (2.0%) |
| Diarrhoea | 21 (10.4%) |
| NSAID (ever) | 107 (53.0%) |
| Corticosteroids (past) | 27 (13.4%) |
| Conventional synthetic DMARDs (past) | 49 (24.3%) |
| TNFi (past) | 21 (10.4%) |
| Conventional synthetic DMARDs (onset) | 53 (26.2%) |
| TNFi (onset) | 63 (31.2%) |
All results are presented as mean±SD for continuous variables and percentages for categorical variables.
ASDAS, Ankylosing Spondylitis Disease Activity Score-CRP; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; CRP, C reactive protein; DMARDs, disease-modifying antirheumatic drugs; HLA-B27, human leucocyte antigen B27; IBD, inflammatory bowel disease; NSAID, non-steroidal anti-inflammatory drug; TNFi, tumour necrosis factor inhibitor.