Epidemiology of Autism Spectrum Disorders

Epidemiologic data gathered over the last 40 years report that the conservative estimate of autistic spectrum disorder prevalence is 27.5 per 10,000 individuals; however, the prevalence estimate based on newer surveys is 60 per 10,000 individuals. Several factors are considered in various epidemiologic surveys of autism, especially the evolution of the concept of autism and changing criteria for diagnosis. This article reviews the incidence, prevalence, and risk factors for autism.