Characteristics of fracture cases and controls with ankylosing spondylitis
| Characteristics | Fracture cases, n (%)(N = 416) | Controls, n (%)(N = 342) | p Value |
| Age | |||
| ⩽30 | 15 (3.6%) | 27 (7.9%) | <0.02 |
| 31–45 | 91 (21.9%) | 72 (21.1%) | NS |
| 45–60 | 121 (29.1%) | 95 (27.8%) | NS |
| ⩾61 | 189 (45.4%) | 148 (43.3%) | NS |
| Sex | |||
| Male | 238 (57.2%) | 204 (59.6%) | NS |
| Female | 178 (42.8%) | 138 (40.4%) | NS |
| Drug use in 6 months before index date | |||
| Sulfasalazine | 7 (1.7%) | 9 (2.6%) | NS |
| NSAIDs | 171 (41.1%) | 138 (40.4%) | NS |
| Oral glucocorticoids | 35 (8.4%) | 14 (4.1%) | 0.02 |
| Hypnotics/anxiolytics | 58 (13.9%) | 32 (9.4%) | NS |
| Medical history | |||
| IBD | 20 (4.8%) | 6 (1.8%) | 0.04 |
| Psoriasis | 26 (6.3%) | 17 (5.0%) | NS |
| Recent back pain (previous 6 months) | 72 (17.3%) | 41 (12.0%) | 0.05 |
| Hip/knee joint replacement | 14 (3.4%) | 16 (4.7%) | NS |
IBD, inflammatory bowel disease; NS, not significant; NSAID, non-steroidal anti-inflammatory disease.