18% Of South Carolina Children With Intellectual Disability Also Have Autism

About 18% of South Carolina children diagnosed with intellectual disability also have co-occurring autism spectrum disorder (ASD). Statewide, from 2002 to 2008, about 0.6% to 1.1% of children have been diagnosed with autism. Diagnostic rates of ASD in intellectual disability generally increased across time. Between 2002 and 2008, the rate of ASD within intellectual disability increased by 48%, from 159 per 1,000 to 235 per 1,000. In 2008, the most recent surveillance year, the proportion of ASD within intellectual disability was 23.5%. During the same period, the rate of ASD only increased by 110 . . .