Table 1.
Descriptive statistics of clusters based on swollen joint data for patients with CASPAR-positive definite PsA at inclusion
| Oligo N = 748 |
Poly N = 16 |
Hands N = 123 |
Feet N = 70 |
P value | |
|---|---|---|---|---|---|
| Female | 46% | 31% | 46% | 39% | 0.46 |
| Age | 48 (40–57) | 55 (50–58) | 50 (44–60) | 45 (41–54) | 0.004 |
| Disease duration | 6 (2–13) | 4 (2–8) | 6 (2–11) | 5 (3–8) | 1 |
| Arthritis ever | 92% | 100% | 100% | 100% | 0.0005 |
| Enthesitis ever | 63% | 70% | 67% | 60% | 0.79 |
| Spinal disease ever | 43% | 38% | 41% | 42% | 0.95 |
| Current skin psoriasis | 83% | 94% | 91% | 97% | 0.001 |
| Psoriasis patient history | 97% | 100% | 98% | 97% | 0.85 |
| Psoriasis family history | 35% | 13% | 38% | 51% | 0.05 |
| Nail psoriasis ever | 29% | 17% | 32% | 33% | 0.87 |
| Negative RF ever | 97% | 90% | 99% | 100% | 0.28 |
| Dactylitis ever | 66% | 94% | 81% | 91% | 0.0005 |
| Radiographic criterion | 31% | 33% | 39% | 33% | 0.63 |
| Oligoarticular | 70% | 0% | 2% | 6% | 0.0005 |
| DIP-predominant | 3% | 0% | 3% | 0% | 0.55 |
| Any DIP involvement | 11% | 38% | 31% | 40% | 0.0005 |
| Symmetric polyarticular | 15% | 100% | 57% | 57% | 0.0005 |
| Inflammatory back pain ever | 34% | 50% | 33% | 31% | 1.00 |
| HLA-B27-positive | 10% | 6% | 7% | 9% | 0.45 |
| Anti-TNF-α | 52% | 38% | 54% | 50% | 0.09 |
| DMARD | 63% | 81% | 65% | 71% | 0.25 |
| Corticosteroids | 9% | 19% | 20% | 13% | 0.0085 |
| NSAID | 52% | 88% | 63% | 80% | 0.0005 |
| SJC66 | 1 (0–4) | 24 (17–34) | 10 (4–12) | 13 (2–17) | <0.0001 |
| SJC28 | 1 (0–2) | 20 (10–22) | 7 (0–10) | 4 (0–7) | <0.0001 |
| CRP [mg/l] | 6 (2–9) | 11 (8–29) | 8 (4–17) | 8 (5–16) | 0.0018 |
| ESR [mm/h] | 10 (5–20) | 29 (15–59) | 14 (6–25) | 16 (11–36) | 0.0001 |
| Physician global | 3 (2–5) | 7 (6–8) | 5 (3–7) | 5 (4–7) | <0.0001 |
| Patient global | 4 (2–7) | 3 (3–7) | 6 (3–7) | 7 (4–8) | <0.0001 |
| Patient pain | 5 (2–7) | 3 (3–9) | 6 (3–8) | 6 (4–8) | <0.0001 |
Data are from the visit used for cluster analysis unless otherwise stated. P values are from Fisher’s exact test for nominal variables or a Wilcoxon rank-sum test for continuous/ordinal variables. No multiple testing correction was performed. For continuous variables, medians and interquartile ranges (in parentheses) and, for nominal variables, proportions (in %) are reported
CRP C-reactive protein, DIP distal interphalangeal, DMARD synthetic disease-modifying anti-rheumatic drugs, ESR erythrocyte sedimentation rate, NSAID non-steroidal anti-inflammatory drugs, RF rheumatoid factor, SJC swollen joint count on the basis of 28/66 joints