Patient characteristics at clinic entry
| No of patients in the analysis | 655 | |
| Mean age at clinic entry (range) | 43.5 (15.5 to 87.5) | |
| Mean age at onset of psoriasis (range) | 28.9 (0 to 84) | |
| Mean age at onset of arthritis (range) | 35.9 (9 to 86) | |
| Mean duration of arthritis (SEM) | 7.5 (2.9) | |
| Mean duration of psoriasis (SEM) | 14.6 (3.5) | |
| ⩾40 years old at onset of psoriasis | 150 (22.9%) | |
| ⩾60 years old at onset of psoriatic arthritis | 34 (5.2%) | |
| Family history of psoriasis | 264 (40.5%) | |
| Family history of psoriatic arthritis | 65 (10%) | |
| Actively inflamed joints | ||
| No with no actively inflamed joints | 43 (6.6%) | |
| No with 1–5 actively inflamed joints | 181 (27.6%) | |
| No with ⩾5 actively inflamed joints | 431 (65.8%) | |
| Deformed Joints | ||
| No with no deformed joints | 402 (61.4%) | |
| No with 1–5 deformed joints | 138 (21.1%) | |
| No with ⩾5 deformed joints | 115 (17.5%) | |
| Mean No of active joints (SEM) | 10.1 (3.1) | |
| Mean No of deformed joints (SEM) | 3.2 (2.8) |