The U.S. Centers for Disease Control and Prevention (CDC) and Health Resources and Services Administration released a report titled “Changes in Prevalence of Parent-reported Autism Spectrum Disorder in School-aged U.S. Children: 2007 to 2011–2012“. The report presents data on the prevalence of diagnosed autism spectrum disorder (ASD) as reported by parents of school-aged children ages 6–17 years in 2011–2012. Data was drawn from the 2007 and 2011–2012 National Survey of Children’s Health, which comprises independent, nationally representative telephone surveys of households with children.

Last year, the CDC’s Autism and Developmental Disabilities Monitoring Network estimated that 1 in 88 children had been identified with ASD. The CDC now estimates that in 2011–2012, about 1 in 50 school-aged children, or 2 percent of children ages 6–17 years have some form of the disorder. Since the average school bus holds 50–55 children, that means, statistically speaking, on average there is one child with parent-reported ASD on every school bus in America.

The agencies conclude that the increase in prevalence of parent-reported ASD was largely due to improved diagnosis of ASD by doctors or other health professional in recent years, especially when the symptoms were mild.