Table 2.
Baseline clinical characteristics for patients in the ReACCh-Out and the Nordic JIA cohort according to severe disease course or non-severe disease course
| Characteristics | ReACCh-Out development cohort | Nordic validation cohort | ||
|---|---|---|---|---|
| Severe disease (n = 125) | Non-severe (n = 484) | Severe disease (n = 98) | Non-severe (n = 342) | |
| Age at onset, years | 9.9 (5.4–12.0), n = 123 | 6.9 (2.5–10.7), n = 474 | 8.1 (2.9–11.0) | 5.2 (2.3–9.0) |
| Female, n (%) | 88 (70.4) | 325 (67.1) | 78 (79.6) | 213 (62.3) |
| Disease onset to diagnosis, months | 5.6 (2.4–13.9) | 3.3 (1.6–6.4) | 2.4 (1.4–5.1), n = 94 | 1.4 (1.4–2.8), n = 321 |
| Disease onset to enrollment, months | 8.8 (4.9–17.0) | 5.5 (2.8–9.9) | 6.0 (6.0–9.0) | 7.0 (6.0–8.0) |
| JIA category, n (%) | ||||
| Oligoarthritis | 9 (7.2) | 214 (44.2) | 27 (27.6) | 200 (58.5) |
| RF-neg. polyarthritis | 44 (35.2) | 85 (17.6) | 37 (37.8) | 57 (16.7) |
| RF-pos. polyarthritis | 20 (16.0) | 6 (1.2) | 3 (3.1) | 1 (0.3) |
| Systemic | 10 (8.0) | 37 (7.6) | 2 (2.0) | 15 (4.4) |
| Enthesitis-related | 24 (19.2) | 57 (11.8) | 9 (9.2) | 25 (7.3) |
| Psoriatic | 4 (3.2) | 32 (6.6) | 1 (1.0) | 5 (1.5) |
| Undifferentiated | 14 (11.2) | 53 (11.0) | 19 (19.4) | 39 (11.4) |
| Active joints, n (%) | ||||
| Cervical arthritis | 21 (16.8) | 8 (1.7) | 22 (22.7) | 16 (4.7) |
| Finger arthritis | 86 (68.8) | 122 (25.2) | 63 (65.0) | 72 (21.1) |
| Ankle arthritis | 78 (62.4) | 140 (28.9) | 61 (62.9) | 137 (40.1) |
| Hip arthritis | 35 (28.0) | 34 (7.0) | 19 (19.6) | 45 (13.2) |
| Cumulative active joint counta | 13 (4–26) | 2 (1–4) | 9 (5–14) | 2 (1–5) |
| Physician global assessment VAS | 5.3 (3.2–7.2) | 2.3 (1.0–4.6) | 2.4 (1.0–4.7), n = 75 | 1.0 (0.3–2.1), n = 173 |
| Parents’ global assessment VAS | 3.6 (1.8–5.7), n = 114 | 1.3 (0.3–3.5), n = 440 | 2.3 (1.0–5.0), n = 76 | 0.9 (0.0–2.5), n = 195 |
| Pain VAS | 5.0 (2.7–6.8), n = 114 | 2.0 (0.5–5.0), n = 440 | 3.4 (1.1–5.0), n = 75 | 0.8 (0.0–2.8), n = 192 |
| CHAQ | 0.9 (0.3–1.4), n = 109 | 0.3 (0.0–0.8), n = 408 | 0.9 (0.3–1.4), n = 78 | 0.1 (0.0–0.7), n = 200 |
| Morning stiffness, n (%) | 102/124 (82.3)b | 334/447 (74.7)b | 60/86 (69.8)c | 60/254 (23.6)c |
| ESR mm/hour | 20 (9–45), n = 119 | 20 (9–36), n = 433 | 16 (8–39), n = 77 | 14 (8–25), n = 281 |
| CRP mg/l | 5.8 (0.4–34.0), n = 98 | 2.0 (0.1–10.0), n = 371 | 0.0 (0.0–22.5), n = 80 | 0.0 (0.0–10.0), n = 274 |
| ANA positive, n (%) | 54 (43.0)d | 233 (48.0)d | 22/95 (23.2) | 93/332 (28.3) |
| RF positive, n (%) | 24 (19.2)d | 21 (4.3)d | 4/70 (5.7) | 6/171 (3.5) |
| HLA B27 positive, n (%) | 18 (14.4)d | 46 (9.5)d | 23/96 (24.0) | 63/314 (20.1) |
| Treatment by first study visit, n (%) | ||||
| NSAIDs | 115/125 (92.0) | 451/484 (93.2) | 83/97 (85.6) | 290/337 (86.1) |
| Joint injections | 9/125 (7.2) | 92/484 (19.0) | 46/95 (48.4) | 195/334 (58.4) |
| DMARDs | 89/125 (71.2) | 114/484 (23.6) | 39/94 (41.5) | 53/320 (16.6) |
| Biologics | 2/125 (1.6) | 0 | 0 | 0 |
Numbers are median interquartile range (IQR) unless otherwise specified
VAS visual analogue scale, CHAQ Childhood Health Assessment Questionnaire, ESR erythrocyte sedimentation rate, CRP C-reactive protein, ANA antinuclear antibodies, RF rheumatoid factor, HLA B27 Human Leucocyte Antigen B27, NSAID non-steroidal anti-inflammatory drug, DMARD disease modifying antirheumatic drug
aThe Nordic cohort used the cumulative joint count within 6 months of disease onset, and the ReACCh-Out cohort used the active joint count at baseline
bMorning stiffness > 30 min
cMorning stiffness > 15 min
dValues on ANA, RF, and HLA B7 for the Canadian cohort are after imputation