| Participants | Non-participants |  | ||||
---|---|---|---|---|---|---|---|
PARENTS | N | M | SD | N | M | SD | Â |
Age (years) | 155 | 41.99 | 5.40 | Â | Â | Â | Â |
 | N | % |  | N | % |  | p |
Country of birth parents (Netherlands) | 139 | 83.7 | Â | 65 | 61.9 | Â | <.001b |
Gender (female) | 147 | 87.5 | Â | Â | Â | Â | Â |
Married/living together | 158 | 94.0 | Â | Â | Â | Â | Â |
Education | Â | Â | Â | Â | Â | Â | Â |
 Low | 22 | 13.1 |  |  |  |  |  |
 Middle | 86 | 51.2 |  |  |  |  |  |
 High | 60 | 35.7 |  |  |  |  |  |
Number of children | Â | Â | Â | Â | Â | Â | Â |
 1 | 22 | 13.1 |  |  |  |  |  |
 2-3 | 135 | 80.3 |  |  |  |  |  |
 > 3 | 11 | 6.6 |  |  |  |  |  |
CHILDREN | N | M | SD | N | M | SD | p |
Age (years) | 168 | 11.48 | 4.56 | 105 | 13.28 | 3.87 | <.001a |
Age of disease onset | 165 | 7.40 | 4.42 | 104 | 8.61 | 4.46 | .03a |
Age of diagnosis | 168 | 8.58 | 4.69 | 103 | 9.72 | 4.52 | .05a |
 | N | % |  | N | % |  | p |
Gender (female) | 113 | 67.3 | Â | 65 | 61.9 | Â | .34b |
JIA subtype | N | % | Â | N | % | Â | p |
 Oligo-articular JIA, persistent | 40 | 13.8 |  | 19 | 18.1 |  | .26b |
 Oligo-articular JIA, extended | 21 | 12.5 |  | 12 | 11.4 |  | .79b |
 Poly-articular JIA, RF negative | 66 | 39.4 |  | 46 | 43.8 |  | .46b |
 Poly-articular JIA, RF positive | 5 | 3.0 |  | 4 | 3.8 |  | .71b |
 Systemic JIA | 7 | 4.2 |  | 3 | 2.9 |  | * |
 Enthesitis related Arthritis | 18 | 10.7 |  | 11 | 10.5 |  | .95b |
 Undifferentiated JIA | 9 | 5.3 |  | 8 | 7.7 |  | .50b |
 Chronic arthritis with other autoimmune inflammatory disease | 2 | 1.2 |  | 2 | 1.9 |  | * |
 | N | Median (range) | N | Median (range) | p |  |  |
Time between symptom onset and diagnosis of JIA (months) | 165 | 0.55 (0–8.78) | 102 | 0.47 (0.1-10.26) |  |  | .19c |
Disease duration (years) | 165 | 3.46 (0.28-14.82) | 102 | 3.77 (0.45-14.13) | Â | Â | .15c |
Physician disease activity (VAS score range 0–100) | 165 | 15.00 (0–84) | 102 | 17.00 (0–94) |  |  | .85c |
Number of joints with arthritis | N | % | Â | N | % | Â | p |
No arthritis | 76 | 45.2 | Â | 46 | 43.8 | Â | .82b |
 Monoarthritis (1 joint) | 21 | 12.5 |  | 18 | 17.1 |  | .29b |
 Oligoarthritis (2–4 joints) | 45 | 26.8 |  | 22 | 21.0 |  | .28b |
 Polyarthritis (>4 joints) | 23 | 13.7 |  | 19 | 18.1 |  | .57b |
 Uveitis presenting during disease course | 8 | 4.8 |  | 9 | 8.6 |  | .45b |
Medication at time point of evaluation | N | % | Â | N | % | Â | p |
 No medication | 13 | 7.7 |  | 16 | 15.2 |  | .05b |
 NSAID | 98 | 58.3 |  | 47 | 44.8 |  | .029b |
 DMARDS (including methotrexate, sulfasalazine) | 131 | 78.0 |  | 76 | 72.4 |  | .38b |
 Anti-TNF | 24 | 14.3 |  | 1 | 9.5 |  | * |
 DMARDS and Biological (Anti-TNF) | 21 | 12.5 |  | 9 | 8.6 |  | .31b |