Risk of OS associated with SpA and non-SpA subtypes
| All OS | Without OS | With OS | Crude OR | 95% CI | AOR | 95% CI |
| N (%) | 205 340 (100) | 8940 (100) | ||||
| Non-SpA (%) | 103 600 (50.5) | 3540 (39.6) | ref | ref | ||
| SpA (%) | 101 740 (49.5) | 5400 (60.4) | 1.553 | 1.488 to 1.622 | 1.648 | 1.577 to 1.723 |
| AS (%) | 59 070 (28.8) | 3221 (36.9) | 1.596 | 1.52 to 1.677 | 1.708 | 1.624 to 1.795 |
| PsA (%) | 35 339 (17.2) | 2030 (22.7) | 1.681 | 1.59 to 1.778 | 1.724 | 1.628 to 1.826 |
| SpA-IBD (%) | 5227 (2.5) | 92 (1) | 0.515 | 0.418 to 0.635 | 0.526 | 0.427 to 0.65 |
| ReA (%) | 2104 (1) | 57 (0.6) | 0.793 | 0.608 to 1.034 | 1.463 | 1.108 to 1.932 |
| THA | ||||||
| N (%) | 210 799 (100) | 3481 (100) | ||||
| Non-SpA (%) | 105 920 (50.2) | 1220 (35) | ref | ref | ||
| SpA (%) | 104 879 (49.8) | 2261 (65) | 1.872 | 1.745 to 2.008 | 2.111 | 1.964 to 2.268 |
| AS (%) | 60 825 (28.9) | 1466 (42.1) | 2.093 | 1.534 to 1.848 | 2.304 | 2.131 to 2.492 |
| PsA (%) | 36 658 (17.4) | 711 (20.4) | 1.684 | 1.534 to 1.848 | 1.905 | 1.732 to 2.095 |
| SpA-IBD (%) | 5256 (2.5) | 63 (1.8) | 1.041 | 0.807 to 1.343 | 1.18 | 0.912 to 1.526 |
| ReA (%) | 2149 (1) | 21 (0.6) | 0.852 | 0.552 to 1.314 | 3.073 | 1.929 to 4.896 |
| TKA | ||||||
| N (%) | 211 956 (100) | 2324 (100) | ||||
| Non-SpA (%) | 105 931 (50) | 1209 (52) | ref | ref | ||
| SpA (%) | 106 025 (50) | 1115 (48) | 0.921 | 0.849 to 1 | 0.97 | 0.892 to 1.054 |
| AS (%) | 61 918 (29.2) | 373 (16) | 0.528 | 0.47 to 0.593 | 0.588 | 0.522 to 0.661 |
| PsA (%) | 36 646 (17.3) | 723 (31.1) | 1.729 | 1.575 to 1.897 | 1.571 | 1.428 to 1.728 |
| SpA-IBD (%) | 5311 (2.5) | 8 (0.3) | 0.132 | 0.066 to 0.265 | 0.164 | 0.081 to 0.329 |
| ReA (%) | 2150 (1) | 11 (0.5) | 0.448 | 0.247 to 0.813 | 3.755 | 1.935 to 7.287 |
| ULA | ||||||
| N (%) | 213 453 (100) | 827 (100) | ||||
| Non-SpA (%) | 106 658 (50) | 482 (58.3) | ref | ref | ||
| SpA (%) | 106 795 (50) | 245 (41.7) | 0.715 | 0.622 to 0.821 | 0.804 | 0.699 to 0.925 |
| AS (%) | 62 166 (29.1) | 125 (15.1) | 0.445 | 0.365 to 0.542 | 0.522 | 0.428 to 0.636 |
| PsA (%) | 37 160 (17.4) | 209 (25.3) | 1.245 | 1.058 to 1.465 | 1.333 | 1.13 to 1.573 |
| SpA-IBD (%) | 5316 (2.5) | 3 (0.4) | 0.125 | 0.04 to 0.389 | 0.107 | 0.034 to 0.332 |
| ReA (%) | 2153 (1) | 8 (1) | 0.822 | 0.408 to 1.656 | 7.939 | 3.04 to 20.733 |
| Arthrodesis | ||||||
| N (%) | 214 033 (100) | 247 (100) | ||||
| Non-SpA (%) | 107 065 (50) | 75 (30.4) | ref | ref | ||
| SpA (%) | 106 968 (50) | 172 (69.6) | 2.295 | 1.75 to 3.011 | 2.454 | 1.866 to 3.228 |
| AS (%) | 62 259 (29.1) | 32 (13) | 0.734 | 0.485 to 1.11 | 0.793 | 0.523 to 1.202 |
| PsA (%) | 37 239 (17.4) | 130 (52.6) | 4.983 | 3.75 to 6.623 | 5.671 | 4.253 to 7.562 |
| SpA-IBD (%) | 5317 (2.5) | 2 (0.8) | 0.537 | 0.132 to 2.187 | 0.382 | 0.093 to 1.558 |
| ReA (%) | 2153 (1) | 8 (3.2) | 5.304 | 2.556 to 11.009 | 12.7 | 4.735 to 34.065 |
| Spinal surgery | ||||||
| N (%) | 212 194 (100) | 2086 (100) | ||||
| Non-SpA (%) | 106 579 (50.2) | 561 (26.9) | ref | ref | ||
| SpA (%) | 105 615 (49.8) | 1525 (73.1) | 2.743 | 2.489 to 3.023 | 2.614 | 2.367 to 2.887 |
| AS (%) | 61 062 (28.8) | 1229 (58.9) | 3.824 | 3.459 to 4.227 | 3.637 | 3.282 to 4.031 |
| PsA (%) | 37 098 (17.5) | 271 (13.0) | 1.388 | 1.2 to 1.605 | 1.39 | 1.2 to 1.611 |
| SpA-IBD (%) | 5303 (2.5) | 16 (0.8) | 0.573 | 0.348 to 0.943 | 0.496 | 0.301 to 0.817 |
| ReA (%) | 2152 (1) | 9 (0.8) | 0.795 | 0.411 to 1.537 | 0.42 | 0.215 to 0.818 |
Variables included in the adjustment, SpA_type, year, age, sex, DM, hypertension, obesity, tobacco use, fx_any, osteoporosis, parasitic infectious diseases, hyperlipidaemia, cardiovascular disease, Charlson comorbidity index.
AOR, adjusted odds ratio; AS, ankylosing spondylitis; OS, orthopaedic surgery; PsA, psoriatic arthritis; SpA-IBD, spondyloarthritis associated with inflammatory bowel disease; THA, total hip arthroplasty; TKA, total knee arthroplasty; ULA, upper limb arthroplasty.