Table 1.
Baseline characteristics of the patients suspected of axSpA in the ASAS, DESIR and SPACE cohort
| Characteristic | ASAS (n = 594) | DESIR (n = 647) | SPACE (n = 577) |
|---|---|---|---|
| Age at baseline, mean (s.d.), years | 33.7 (11.7) | 33.6 (8.6) | 30.8 (8.1) |
| Male, n (%) | 276 (46) | 305 (47) | 221 (38) |
| Caucasian, n (%) | 348 (59) | 577 (89) | 454/484 (94) |
| Duration of back pain, mean (s.d.), months | 85.7 (108.4)a | 18.2 (10.6)a | 13.3 (7.1) |
| IBP, n (%) | 301/532 (57) | 647 (100)b | 396/576 (69) |
| Good response to NSAIDsc, n (%) | 274 (46) | 515/644 (80) | 263/563 (47) |
| Peripheral arthritis, n (%) | 197 (33) | 363 (56) | 97/575 (17) |
| Enthesitis, n (%) | 241 (41) | 312 (48) | 121 (21) |
| Dactylitis, n (%) | 23 (4) | 83 (13) | 35 (6) |
| AAU, n (%) | 53 (9) | 51 (8) | 47 (8) |
| Psoriasis, n (%) | 22 (4) | 97 (15) | 77 (13) |
| IBD, n (%) | 8 (1) | 23 (4) | 38 (7) |
| Positive family history according to ASAS definition, n (%) | 135 (23) | 249 (39) | 218 (38) |
| A positive family history of | |||
| AS, n (%) | 87 (15) | 127 (20) | 104 (18) |
| AAU, n (%) | 7 (1) | 29 (4) | 34 (6) |
| ReA, n (%) | 8 (1) | 6 (1) | 19/563 (3) |
| IBD, n (%) | 12 (2) | 32 (5) | 32/570 (6) |
| Psoriasis, n (%) | 36 (6) | 129 (20) | 95/571 (17) |
| HLA-B27 positivity, n (%) | 310 (52) | 376/646 (58) | 246 (43) |
| Elevated CRP/ESR, n (%) | 185 (31) | 254 (39) | 188 (33) |
| Radiographic sacroiliitisd, n (%) | 119/593 (20) | 172 (27) | 80/570 (14) |
| Sacroiliitis on MRId, n (%) | 189/424 (45) | 207/636 (33) | 207/565 (37) |
| Clinical diagnosis of axSpAe, n (%) | 368 (62) | 302 (47) | 313 (54) |
a
<5% missing values.
b
Inclusion criterion.
c
Back pain not present anymore or is much better 24–48 h after a full dose of NSAID.
d
Imaging based on local reading of the SI joints.
e
Level of confidence regarding the diagnosis is ≥6 in ASAS and SPACE, ≥8 in DESIR. AAU: acute anterior uveitis; ASAS: Assessment of SpondyloArthritis international Society; (ax)SpA: (axial) spondyloarthritis; DESIR: DEvenir des Spondyloarthropathies Indifférenciéés Récentes; IBP: inflammatory back pain; SPACE: SPondyloArthritis Caught Early.