Characteristics of the patients with AS and matched control at start of follow-up
| AS | Matched controls | |||
| Men N=7605 | Women N=4006 | Men N=38 020 | Women N=20 030 | |
| Age, mean (SD) | 49 (15) | 47 (14) | 49 (15) | 47 (14) |
| 18-29 years, n (%) | 867 (11.4) | 503 (12.6) | 4330 (11.4) | 2515 (12.6) |
| 30–39 years, n (%) | 1429 (18.8) | 806 (20.1) | 7145 (18.8) | 4030 (20.1) |
| 40–49 years, n (%) | 1621 (21.3) | 992 (24.8) | 8105 (21.3) | 4960 (24.8) |
| 50–59 years, n (%) | 1654 (21.7) | 850 (21.2) | 8270 (21.8) | 4250 (21.2) |
| 60–69 years, n (%) | 1410 (18.5) | 593 (14.8) | 7050 (18.5) | 2965 (14.8) |
| 70–79 years, n (%) | 524 (6.9) | 203 (5.1) | 2620 (6.9) | 1015 (5.1) |
| 80+ years, n (%) | 100 (1.3) | 59 (1.5) | 500 (1.3) | 295 (1.5) |
| Prior medical conditions | ||||
| Any fracture | 538 (7.1) | 269 (6.7) | 2153 (5.7) | 1048 (5.2) |
| Vertebral fracture | 137 (1.8) | 47 (1.2) | 170 (0.4) | 74 (0.4) |
| Non-vertebral fracture | 422 (5.5) | 234 (5.8) | 2002 (5.3) | 988 (4.9) |
| Fracture of the humerus, forearm or hip | 112 (1.5) | 105 (2.6) | 429 (1.1) | 417 (2.1) |
| Proximal humerus fracture | 25 (0.3) | 32 (0.8) | 80 (0.2) | 82 (0.4) |
| Distal forearm fracture | 66 (0.9) | 63 (1.6) | 274 (0.7) | 296 (1.5) |
| Hip fracture | 23 (0.3) | 14 (0.3) | 84 (0.2) | 60 (0.3) |
| Fall injury | 848 (11.2) | 439 (11.0) | 3744 (9.8) | 1753 (8.8) |
| Osteoporosis | 75 (1.0) | 90 (2.2) | 56 (0.1) | 114 (0.6) |
| Anterior uveitis | 1629 (21.4) | 743 (18.5) | 254 (0.7) | 95 (0.5) |
| Inflammatory bowel disease | 468 (6.2) | 271 (6.8) | 316 (0.8) | 160 (0.8) |
| Psoriasis | 230 (3.0) | 148 (3.7) | 577 (1.5) | 265 (1.3) |
| Medical treatment | ||||
| DMARDs | 2444 (32.1) | 1233 (30.8) | 321 (0.8) | 196 (1.0) |
| TNF inhibitors | 1121 (14.7) | 527 (13.2) | 30 (0.1) | 17 (0.1) |
| sDMARDs | 1786 (23.5) | 951 (23.7) | 310 (0.8) | 191 (1.0) |
| Peroral glucocorticoids | 1325 (17.4) | 796 (19.9) | 1212 (3.2) | 891 (4.4) |
| 1 prescription | 516 (6.8) | 363 (9.1) | 687 (1.8) | 532 (2.7) |
| ≥2 prescriptions | 809 (10.6) | 433 (10.8) | 525 (1.4) | 359 (1.8) |
| Bisphosphonate* | 168 (2.2) | 178 (4.4) | 118 (0.3) | 221 (1.1) |
| Calcium, vitamin D | 472 (6.2) | 489 (12.2) | 323 (0.8) | 606 (3.0) |
| Oestrogens | 0 (0.0) | 448 (11.2) | 1 (0.0) | 1533 (7.7) |
The data are presented as n (%) if not stated otherwise. Prior medical conditions were identified in the National Patient Register within 6 years before start of follow-up. Medical treatment with ≥1 prescription identified in the Prescribed Drug Register (irrespective of indication) or the Swedish Rheumatology Quality Register within 1 year before start of follow-up.
*Intravenously administered bisphosphonate not captured in PDR.
AS, ankylosing spondylitis; DMARDs, disease modifying anti-rheumatic drugs; PDR, Prescribed Drug Register; sDMARDs, synthetic DMARDs; TNF, tumour necrosis factor.