Table 1 Demographic and clinical characteristics of the juvenile idiopathic arthritis patients from different registries
Pharmachild N = 8274 | BiKeR N = 3990 | Sweden N = 3020 | |
|---|---|---|---|
Number of countries | 32 | 2# | 1 |
Number of centers | 86 | 72 | 33 |
Number of patients per center | 55.5 (17–124) | 10.5 (3–39.8) | 52 (31–78) |
Age at onset | 5.4 (2.4–10.0) | 7.6 (3.2–11.7) | 7.6 (2.9–11.7)1 |
Age at JIA diagnosis | 6.2 (2.8–10.9) | – | 8.3 (3.5–12.8)2 |
Disease duration at last visit | 5.3 (2.7–8.8) | 6.1 (3.5–9.5) | 6.8 (4.3–10.1)3 |
Female | 5584 (67.5%) | 2670 (66.9%) | 1989 (65.9%) |
Antinuclear antibodies (ANA)* | 1767 (21.4%) | 1900 (47.6%) | – |
ILAR JIA category | 4 | 5 | |
Systemic | 911 (11.0%) | 267 (6.7%) | 109 (4.7%) |
Oligo | 3071 (37.1%) | 1215 (30.5%) | 1148 (49.6%) |
Oligo persistent | 2011 (24.3%) | 494 (12.4%) | – |
Oligo extended | 1060 (12.8%) | 721 (18.1%) | – |
Polyarticular RF− | 2183 (26.4%) | 1192 (29.9%) | 568 (24.6%) |
Polyarticular RF+ | 322 (3.9%) | 243 (6.1%) | 85 (3.7%) |
Psoriatic arthritis | 285 (3.4%) | 296 (7.4%) | 160 (6.9%) |
Enthesitis-related arthritis | 924 (11.2%) | 649 (16.3%) | 185 (8.0%) |
Undifferentiated arthritis | 578 (7.0%) | 127 (3.2%) | 58 (2.5%) |