Brugha. T., Cooper. S. A., McManus. S., Purdon. S., Smith. J., Scott. F. J., Spiers. N., Tyrer. F.
NHS, 2007

Key facts

• The overall prevalence of autism, combining data from the APMS 200712 and learning disability study, was 1.1 per cent (95 per cent confidence interval 0.3 per cent to 1.9 per cent). o The prevalence of autism was higher in men (2.0 per cent) than women (0.3 per cent).

• In the learning disability study it was found that the prevalence of autism increased with greater severity of learning disability/lower verbal IQ.

• Among adults with learning disabilities living in private households whose learning disability was sufficiently severe that they could not have taken part in the APMS 200712, the prevalence of autism was 35.4 per cent (95 per cent confidence interval 24.7 per cent to 46.2 per cent). Among adults with mild or severe learning disabilities living in communal care establishments, the prevalence of autism was 31.0 per cent (95 per cent confidence interval 23.9 per cent to 38.0 per cent). o Sex differences were less marked in adults with learning disabilities compared with the rest of the general population (APMS 200712).

• The estimated prevalence of autism changed very little when the data were re-analysed to take into account that the prevalence of autism might be higher or lower in other settings, such as prisons or defence establishments. Using assumptions based on different scenarios to take these into account, the overall prevalence of autism was estimated at between 1.1 per cent and 1.2 per cent.

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