Table 2.
Characteristics of the study population in the primary analyses
| Disease/disorder | n (per 10 000) | Mean age in 2015 | Females (%) | Maternal education % | |||
|---|---|---|---|---|---|---|---|
| Low (< 10 years) | Medium (10–12 years) | High (> 12 years) | Information missing | ||||
| Total study sample | 2,500,118 | 25.8 | 1,219,669 (48.8) | 23.1 | 42.0 | 33.9 | 0.1 |
| ADHD | 63,721 (255) | 23.4 | 22,878 (35.9) | 31.5 | 42.1 | 25.7 | 0.7 |
| Ankylosing spondylitis | 3504 (14) | 37.4 | 1480 (42.2) | 28.9 | 47.6 | 23.0 | 0.5 |
| Crohn’s disease | 6292 (25) | 32.1 | 3284 (52.2) | 27.6 | 46.0 | 25.9 | 0.5 |
| Iridocyclitis | 7596 (30) | 34.0 | 3470 (45.7) | 26.3 | 46.7 | 26.6 | 0.4 |
| Multiple sclerosis | 3739 (15) | 38.1 | 2621 (70.1) | 29.6 | 49.6 | 20.5 | 0.4 |
| Psoriasis | 62,418 (250) | 33.8 | 32,190 (51.6) | 29.6 | 46.2 | 23.7 | 0.6 |
| Rheumatoid arthritis | 8560 (34) | 37.2 | 5662 (66.1) | 30.9 | 47.8 | 20.8 | 0.4 |
| SLE | 1197 (5) | 35.9 | 1024 (85.5) | 30.2 | 45.6 | 23.6 | 0.7 |
| Type 1 diabetes | 14,273 (57) | 29.5 | 6041 (42.3) | 23.7 | 46.4 | 29.6 | 0.4 |
| Ulcerative colitis | 10,960 (44) | 34.3 | 5392 (49.2) | 26.3 | 47.3 | 26.0 | 0.4 |
ADHD attention-deficit/hyperactivity disorder, SLE systemic lupus erythematosus