Table 1.
Participant characteristics (Nparticipant = 429)
| Participant, N (%) | |
|---|---|
| Total | 429 (100.0) |
| Female | 197 (45.9) |
| Age (years) on 1 January 2006 | |
| 10–13 | 113 (26.3) |
| 14–16 | 272 (63.4) |
| 17–20 | 44 (10.3) |
| School type | |
| Special education unit | 196 (45.7) |
| Special education school | 227 (52.9) |
| High support need school | 6 (1.4) |
| Socioeconomic status (thirds)a | |
| Advantaged | 187 (43.6) |
| Medium | 140 (32.6) |
| Disadvantaged | 102 (23.8) |
| General healtha | |
| Excellent | 113 (26.4) |
| Very good | 145 (33.8) |
| Good | 128 (29.8) |
| Fair | 37 (8.6) |
| Poor | 6 (1.4) |
| Communicationa,b | |
| Verbal | 321 (75.0) |
| Some verbal with non-verbal aids | 59 (13.8) |
| Non-verbal | 48 (11.2) |
| Mobilitya | |
| Walks independently | 367 (85.5) |
| Walks with aids | 57 (13.3) |
| Immobile | 5 (1.2) |
| Cause of intellectual disabilitya | |
| Down syndrome | 65 (15.2) |
| Other known cause | 234 (54.5) |
| Unknown cause | 130 (30.3) |
| Psychopathologya,c | |
| No disturbance | 129 (30.4) |
| Disturbance | 295 (69.6) |
| Epilepsya | 83 (19.3) |
| Autismd | 76 (17.7) |
| ADHDd | 61 (14.2) |
| Mental disorderd | |
| Sleep disorders | 38 (8.9) |
| Affective disorders | 27 (6.3) |
| Anxiety | 21 (4.9) |
| Symptoms and signs involving emotional state | 13 (3.0) |
| Symptoms and signs involving general sensations and perceptions | 10 (2.3) |
| Reaction to severe stress, and adjustment disorders | 10 (2.3) |
| Other mental disorderse | 12 (2.8) |
| Challenging behaviourd | 114 (26.6) |
ADHD, attention-deficit hyperactivity disorder.
a.
Carer reported.
b.
Missing data for one participant.
c.
Missing data for five participants.
d.
Clinician diagnosed.
e.
Other mental disorders includes obsessive–compulsive disorder (four adolescents), specific personality disorders (three adolescents), unspecified nonorganic psychosis (two adolescents), mental and behavioural disorders owing to use of tobacco (one adolescent), schizophrenia (one adolescent), persistent delusional disorders (one adolescent), acute and transient psychotic disorders (one adolescent) and eating disorders (one adolescent).