Table 1.
Baseline characteristics
| Patient characteristics | IA (n=2050) | RA (n=1308) | PsA (n=356) | SpA (n=386) | Controls (n=939) |
| Age, years | 57±13 | 60±12 | 57±12 | 51±13 | 55±13 |
| Women | 1266 (63) | 920 (70) | 167 (47) | 179 (46) | 636 (69) |
| Disease characteristics | |||||
| Disease duration, years | 13 (6–22) | 12 (6–21) | 13 (6–21) | 15 (7–27) | n/a |
| PROMs (0–10) | |||||
| RAPID-3 | 3.0 (1.5–5.5) | 3.0 (1.5–5.5) | 3.0 (1.5–5.5) | 3.5 (2.0–5.3) | n/a |
| VAS disease activity | 3.0 (2.0–4.0) | 3.0 (2.0–4.0) | 3.0 (2.0–4.0) | 3.5 (2.0–5.0) | n/a |
| VAS pain | 3.5 (1.5–6.0) | 3.5 (1.0–6.0) | 3.5 (1.0–6.0) | 4.0 (2.0–6.0) | n/a |
| NSAIDs | 450 (22) | 213 (16) | 60 (17) | 177 (46) | 18 (2) |
| Prednisone | 202 (10) | 174 (13) | 18 (5) | 10 (3) | n/a |
| DMARD | 1588 (78) | 1073 (82) | 276 (78) | 239 (62) | n/a |
| csDMARD | 1118 (55) | 900 (69) | 186 (52) | 32 (8) | n/a |
| Methotrexate | 906 (44) | 733 (56) | 164 (46) | 9 (2) | n/a |
| Hydroxychloroquine | 225 (11) | 218 (17) | 7 (2) | 0 (0) | n/a |
| Leflunomide | 63 (3) | 51 (4) | 9 (3) | 3 (1) | n/a |
| Sulfasalazine | 120 (6) | 90 (7) | 11 (3) | 19 (5) | n/a |
| Other | 16 (1) | 9 (1) | 5 (1) | 2 (1) | n/a |
| bDMARD | 895 (44) | 508 (39) | 169 (47) | 218 (57) | n/a |
| TNF-inhibitor | 727 (36) | 383 (29) | 147 (42) | 197 (51) | n/a |
| IL-6 inhibitor | 32 (2) | 32 (2) | 0 (0) | 0 (0) | n/a |
| IL-12/23 inhibitor | 6 (0) | 0 (0) | 6 (1) | 0 (0) | n/a |
| IL-17 inhibitor | 37 (2) | 0 (0) | 15 (4) | 22 (6) | n/a |
| Rituximab | 48 (2) | 47 (4) | 0 (0) | 0 (0) | n/a |
| Abatacept | 48 (2) | 46 (4) | 2 (1) | 0 (0) | n/a |
| tsDMARD | 20 (1) | 11 (1) | 5 (1) | 4 (1) | n/a |
| JAK-inhibitor | 17 (1) | 11 (1) | 2 (1) | 4 (1) | n/a |
| Apremilast | 3 (0) | 0 (0) | 3 (1) | 0 (0) | n/a |
Data are reported as mean±SD, median (inner quartiles) or frequency (percentage) where appropriate.
bDMARD, biological DMARD; csDMARD, conventional synthetic DMARD; DMARD, disease-modifying anti-rheumatic drug; IA, inflammatory arthritis; IL, interleukin; JAK, janus kinase; NSAIDs, non-steroidal anti-inflammatory drugs; PROM, patient-reported outcome measure; PsA, psoriatic arthritis; RA, rheumatoid arthritis; RAPID, Routine Assessment of Patient Index Data; SpA, (axial) spondyloarthritis; TNF, tumour necrosis factor; tsDMARD, targeted synthetic DMARD; VAS, Visual Analogue Scale.