Table 2.
Baseline characteristics of the test-retest population
| RA | PsA | SpA | p-value | |
|---|---|---|---|---|
| (n = 10) | (n = 10) | (n = 10) | ||
| Female sex n (%) | 8 (80) | 5 (50) | 4 (40) | 0.266 |
| Age (years) | 65 (62–68) | 58.5 (49–67) | 47 (32–52) | 0.005a |
| Duration (years) | 15.5 (8–24) | 8.5 (5–14) | 4 (2–6) | 0.017b |
| DMARD n (%) | 9 (90) | 9 (90) | 2(20) | 0.003 |
| Biologics n (%) | 6 (60) | 7 (70) | 8(80) | 0.879 |
| DAS28-CRP | 3.9 (3.7–4.2) | 3.7 (3.1–4.4) | - | 0.519 |
| TJC 28 | 5.5 (4–10) | 6 (2–9) | - | 0.791 |
| SJC 28 | 1 (1–4) | 0 (0–0) | - | 0.020 |
| BASDAI (0–100) | - | 67 (34–83) | 28 (14–43) | 0.364 |
| BASFI (0–100) | - | 60.5 (37–89) | 18 (13–32) | 0.212 |
| ASDAS | - | 3.05 (2.4–3.8) | 2.1 (1.1–2.7) | 0.104 |
| VAS pain mm | 43 (26–53) | 61.5(25–73) | 24.5 (19–41) | 0.331 |
| VAS fatigue mm | 65 (40–79) | 63.5 (32–82) | 43 (26–67) | 0.397 |
| VAS global mm | 50 (34–63) | 72 (32–87) | 29.5 (22–57) | 0.219 |
| HAQ | 1.25 (0.875–2) | - | - | - |
| Crp mg/l | 5.5 (1–10) | 4 (1–8) | 3.5 (1–9) | 0.939 |
| HLA-B27 n (%) | - | 2(100)(n = 2) | 3(75)(n = 4) | 1 |
| IgM-RF n (%) | 5(50) | - | - | - |
| Anti-CCP n (%) | 5(50) | - | - | - |
Except where indicated otherwise values are the median (interquartile range). P- values are calculated by Kruskal-Wallis or Fishers exact test. asignificant difference between only RA-SpA and SpA-PsA. bsignificant difference between only RA-SpA. DMARD Disease Modifying Anti-Rheumatic Drug, DAS28-crp Disease Activity Score 28 –crp, TJC Tender Joint Count, SJC Swollen Joint Count, BASDAI Bath Ankylosing Spondylitis Disease Activity Index, ASDAS Ankylosing Spondylitis Disease Activity Score, VAS Visual Analogue Scale, HAQ Health Assessment Questionnaire, HLA-B27 Human Leucocyte Antigen-B27, IgM-RF Immunoglobulin M Rheumatoid Factor, Anti-CCP Anti–citrullinated protein antibodies