Table 1.
Prevalence of autism/ADHD and physical health conditions in the total sample and subsamples by sex/zygosity
| Full sample (N) | Total | MZF | DZF | MZM | DZM | DZOS | Unknown | Sample for twin model analysisa | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 32,250 | 4,934 | 5,184 | 4,600 | 5,976 | 11,010 | 546 | 20,694 | |||||||||
| N | % | N | % | N | % | N | % | N | % | N | % | N | % | % | 95% CI | |
| Clinical autism | 534 | 1.7 | 33 | 0.7 | 60 | 1.2 | 85 | 1.8 | 151 | 2.5 | 189 | 1.7 | 16 | 2.9 | 1.6 | 1.4, 1.8 |
| Subclinical autism | 1,251 | 3.9 | 96 | 1.9 | 157 | 3.0 | 211 | 4.6 | 328 | 5.5 | 434 | 3.9 | 25 | 4.6 | 4.0 | 3.7, 4.3 |
| Clinical ADHD | 1,427 | 4.4 | 117 | 2.4 | 169 | 3.3 | 240 | 5.2 | 369 | 6.2 | 501 | 4.6 | 31 | 5.7 | 4.3 | 4.0, 4.7 |
| Subclinical ADHD | 3,607 | 11.2 | 340 | 6.9 | 490 | 9.5 | 602 | 13.1 | 886 | 14.8 | 1,214 | 11.0 | 75 | 13.7 | 11.3 | 10.9, 11.8 |
| Neurological disorders | ||||||||||||||||
| Epilepsy | 392 | 1.2 | 57 | 1.2 | 56 | 1.1 | 51 | 1.1 | 92 | 1.5 | 128 | 1.2 | 8 | 1.5 | 1.2 | 1.1, 1.4 |
| Migraine | 522 | 1.6 | 81 | 1.6 | 106 | 2.0 | 58 | 1.3 | 102 | 1.7 | 171 | 1.6 | 4 | 0.7 | 1.7 | 1.5, 1.9 |
| Other headache | 267 | 0.8 | 55 | 1.1 | 50 | 1.0 | 26 | 0.6 | 33 | 0.6 | 100 | 0.9 | 3 | 0.5 | 0.8 | 0.7, 0.9 |
| Mixed headache | 730 | 2.3 | 126 | 2.6 | 144 | 2.8 | 80 | 1.7 | 127 | 2.1 | 247 | 2.2 | 6 | 1.1 | 2.3 | 2.1, 2.5 |
| Immunological disorders | ||||||||||||||||
| Allergic rhinitis | 1,920 | 6.0 | 244 | 4.9 | 234 | 4.5 | 301 | 6.5 | 445 | 7.4 | 670 | 6.1 | 26 | 4.8 | 5.9 | 5.6, 6.3 |
| Asthma | 4,317 | 13.4 | 514 | 10.4 | 695 | 13.4 | 598 | 13.0 | 960 | 16.1 | 1,476 | 13.4 | 74 | 13.6 | 13.4 | 12.8, 13.9 |
| Atopic dermatitis | 1,647 | 5.1 | 242 | 4.9 | 261 | 5.0 | 205 | 4.5 | 341 | 5.7 | 565 | 5.1 | 33 | 6.0 | 5.1 | 4.7, 5.4 |
| Specific allergy | 643 | 2.0 | 90 | 1.8 | 83 | 1.6 | 107 | 2.3 | 122 | 2.0 | 234 | 2.1 | 7 | 1.3 | 1.9 | 1.7, 2.2 |
| Coeliac disease | 362 | 1.1 | 72 | 1.5 | 73 | 1.4 | 29 | 0.6 | 52 | 0.9 | 131 | 1.2 | 5 | 0.9 | 1.1 | 0.9, 1.3 |
| Gastrointestinal disorders | ||||||||||||||||
| Constipation | 2,035 | 6.3 | 271 | 5.5 | 345 | 6.7 | 258 | 5.6 | 400 | 6.7 | 728 | 6.7 | 33 | 6.0 | 6.2 | 5.8, 6.5 |
| Functional diarrhea | 187 | 0.6 | 31 | 0.6 | 35 | 0.7 | 24 | 0.5 | 39 | 0.7 | 54 | 0.5 | 4 | 0.7 | 0.6 | 0.5, 0.7 |
| Irritable bowel syndrome | 127 | 0.4 | 30 | 0.6 | 25 | 0.5 | 7 | 0.2 | 11 | 0.2 | 53 | 0.5 | 1 | 0.2 | 0.4 | 0.3, 0.4 |
| Mixed FGIDs | 2,283 | 7.1 | 320 | 6.5 | 390 | 7.5 | 283 | 6.2 | 431 | 7.2 | 821 | 7.5 | 38 | 7.0 | 6.9 | 6.5, 7.3 |
The physical health conditions in this study did not include the data from primary care health services
ADHD, attention-deficit/hyperactivity disorder; DZF, dizygotic female; DZM, dizygotic male; DZOS, dizygotic opposite sex; FGIDs, functional gastrointestinal disorders; MZF, monozygotic female; MZM, monozygotic male
aMZ and same-sex DZ twins