Demographic and clinical data of patients with PsA and SpA in private and academic Belgian practices
| Patients with axSpA, n=176 | Patients with SpA,* n=213 | Patients with PsA, n=312 | P value† | |
| Age at inclusion, years (mean±SD) | 34.3±9.9 | 34.9±10.8 | 53.7±12.5 | <0.0001 |
| Age at disease onset, years (mean±SD) | 30.5±9.9 | 31.5±10.7 | 41.3±15.3 | <0.0001 |
| Disease duration, years (mean±SD) | 8.6±9.3 | 7.7±9.3 | 8.3±9.7 | 0.479 |
| Female sex, n (%) | 81 (46.0) | 98 (46.0) | 140 (44.9) | 0.797 |
| HLA-B27 positive‡, n (%) | 136/173 (78.6) | 160/209 (76.6) | 24/136 (17.6) | |
| IBP§, n (%) | 170 (96.6) | 181 (85.0) | 58 (18.6) | <0.0001 |
| Positive family history, n (%) | 52 (29.5) | 58 (27.2) | 157 (50.3) | <0.0001 |
| Psoriasis <40 years, n (%) | None¶ | None¶ | 193 (61.9) | NA |
| Peripheral arthritis, n (%) | 37 (21.0) | 69 (32.4) | 102 (32.7) | 0.294 |
| Dactylitis, n (%) | 16 (9.1) | 32 (15.0) | 45 (14.4) | 0.699 |
| Heel enthesitis, n (%) | 22 (12.5) | 34 (16.0) | 82 (26.3) | 0.005 |
| Uveitis, n (%) | 24 (13.6) | 25 (11.7) | 15 (4.8) | 0.004 |
| IBD, n (%) | 11 (6.4) | 15 (7.0) | 2 (0.6) | <0.0001 |
| Good response to NSAIDs, n (%) | 144 (81.8) | 159 (74.6) | 142 (45.5) | <0.0001 |
| Elevated ESR/CRP, n (%) | 35 (19.9) | 50 (23.5) | 50 (16.0) | 0.033 |
| CRP, mg/L (mean±SD) | 5.6±3.8 | 5.7±3.8 | 6.1±11.0 | 0.610 |
*For this study patients from the (Be-)GIANT cohort without psoriasis were selected.
†Between patients with PsA and all patients with (axial and peripheral) SpA.
‡HLA-B27 typing was missing in 176 patients (BEPAS-cohort) and 4 patients ((Be-)GIANT cohort).
§IBP according to ASAS definition.
¶SpA group contains 176 patients with axial SpA and 37 peripheral patients with SpA originated from the (Be-)GIANT cohort.
ASAS, Assessment of SpondyloArthritis international Society; axSpA, axial spondyloarthritis; (Be-)GIANT, Ghent and BelGian Inflammatory Arthritis and spoNdylitis cohorTs; BEPAS, Belgian Epidemiological Psoriatic Arthritis Study; CRP, C reactive protein; ESR, erythrocyte sedimentation rate; HLA-B27, human leucocyte antigen B27; IBD, inflammatory bowel disease; IBP, inflammatory back pain; NSAIDs, non-steroidal anti-inflammatory drugs; PsA, psoriatic arthritis; SpA, spondyloarthritis.