Attributed pre-existing medical conditions. Total population survey, Australia, 2002/03–2011/12 (n=53)
| Direct cause | Possible contributory | No impact | Total | |
| Epilepsy | 16 | 1 | 2 | 19 |
| Autism, psychological adjustment problems | 0 | 12 | 1 | 13 |
| Intellectual disabilities | 2 | 2 | 1 | 5 |
| Other medical syndromes | 2 | 0 | 8 | 10 |
| Asthma | 0 | 0 | 4 | 4 |
| Neuromuscular disease, paralysis | 1 | 1 | 0 | 2 |
| Total | 21 | 16 | 16 | 53 |