Myomancy ADHD, Dyslexia and Autism

The BBC is reporting that one in 100 British children may have some form of autism. This figure comes from research by Dr Gillian Baird who is a Consultant Developmental Paediatrician at Guy’s Hospital in London.

Researchers from Guy’s and St Thomas’ Hospital in south London, publishing their findings in the Lancet, looked at a group of 57,000 children aged nine and 10 in 2001.
Current provision for those with the disability is deeply inadequate given the scale of the need Mike Collins, National Autistic Society
They identified 255 who had already been diagnosed as having autistic disorders and 1,515 judged to be possible undetected cases.
A randomly selected sub-group of 255 children was chosen for in-depth clinical assessment.
The prevalence of “classic” childhood autism was 39 per 10,000, and that of other ASDs 77 per 10,000.
In total, autistic disorders affected 116 per 10,000 children.
The researchers extrapolated their findings to suggest one in 100 British children may have some form of autism.

The research has been published in The Lancet. I don’t have access to the full study so its not clear how they identified autism and autistic spectrum disorders. This is the key to the research. Are they throwing the net so large they are catching dyslexics or people with ADHD?