Researchers who surveyed children aged five to nine in Cambridgeshiresay the findings should help education, health and social servicesprepare for the future.
Their figures, published in the June issue of the British Journal ofPsychiatry, confirm that one per cent of primary school children have anexisting diagnosis of autism, but also suggest that there may be manymore currently undiagnosed.
The National Autistic Society called for the research to be replicatedmore widely. Chief executive Mark Lever said, 'This is importantresearch, which for the first time gives us an estimate of the number ofpeople who don't have an autism diagnosis but may be in need of support.Access to appropriate diagnostic services is crucial.'
The research team, led by Professor Simon Baron-Cohen at the AutismResearch Centre at Cambridge University, used three different methods toestimate the prevalence of autism spectrum conditions in children at 79schools in and around Cambridge.
They surveyed children using the Special Educational Needs registers,then surveyed parents of 11,700 children in the area. Of the 3,373completed surveys, 41 cases of autism spectrum conditions wereconfirmed. The same parents were asked to complete a Childhood AutismScreening Test, which found an additional 11 children.
The researchers said that, if the figures were extrapolated to the widerpopulation, for every three known cases there may be a further twoundiagnosed.
Professor Baron-Cohen said the study - published in June's BritishJournal of Psychiatry - was particularly significant because it combinedinformation from three different sources.
