Table 1 Characteristics of juvenile idiopathic arthritis trial cohort after median 9 years' follow‐up, by original treatment group*.
| Variable | Placebo group n = 29 | Sulfasalazine group n = 32 | p value |
|---|---|---|---|
| Females | 20 (69%) | 21 (66%) | 0.8 |
| Age, median years (range) | 19 (10 to 23) | 16 (10 to 25) | 0.1 |
| Disease duration, median years (range) | 10 (8 to 20) | 11 (8 to 23) | 0.3 |
| Onset type JCA (EULAR classification)(14) | |||
| Oligoarticular | 15 (52%) | 18 (56%) | 0.8 |
| Polyarticular | 14 (48%) | 14 (44%) | |
| Antinuclear antibody positive at onset | 12 (46%) | 16 (52%) | 0.8 |
| Age at onset JIA, median years (range) | 8 (2 to 14) | 3 (1 to 15) | 0.02§ |
| Age at start SSZ trial inclusion, median, years (range) | 11 (3 to 15) | 8 (3 to 17) | 0.1 |
| Disease duration at start DMARD therapy: median, years (range)† | 1.8 (0.5 to 12) | 2.1 (0.4 to 13.2) | 0.6 |
| Oligoarticular onset JCA patients | 2.5 (0.5 to 12.3)‡ | 3.0 (0.5 to 13.2)‡ | 0.8 |
| Polyarticular onset JCA patients | 1.1 (0.7 to 5.5) | 1.5 (0.4 to 6.2) | 0.6 |
| Diagnosis of uveitis during disease course | 3 (10%) | 9 (28%) | 0.08 |
| Current JIA subtype classification (ILAR classification)(17) | |||
| Oligoarticular persistent | 4 (14%) | 4 (13%) | 0.8 |
| Oligoarticular extended | 7 (24%) | 9 (28%) | 0.7 |
| Polyarticular rheumatoid factor negative | 8 (28%) | 8 (25%) | 0.8 |
| Polyarticular rheumatoid factor positive | 7 (24%) | 3 (9%) | 0.1 |
| Arthritis and psoriasis | – | 2 (6%) | 0.2 |
| Arthritis and enthesitis | 2 (7%) | 5 (16%) | 0.3 |
| Other arthritis | 1 (3%) | 1 (3%) | 0.9 |
*Values are the number (percentage) of patients unless otherwise indicated; †at follow‐up, 2 placebo‐allocated patients had never used DMARDs; ‡in both treatment groups, disease duration before initiation of DMARD therapy was significantly longer in oligoarticular—compared with polyarticular onset JCA patients (p = 0.002); §SSZ allocated patients were significantly younger at disease onset but were of a similar age at SSZ trial inclusion. When all rheumatoid factor‐positive JIA patients were excluded from analysis (n = 10), all characteristics were roughly similar in both treatment groups (data not shown)