Data & Statistics Prevalence
Data & Statistics
Risk Factors and Characteristics
- Studies have shown that among identical twins, if one child has ASD, then the other will be affected about 36-95% of the time. In non-identical twins, if one child has ASD, then the other is affected about 0-31% of the time.
- Parents who have a child with ASD have a 2%–18% chance of having a second child who is also affected.
- ASD tends to occur more often in people who have certain genetic or chromosomal conditions. About 10% of children with autism are also identified as having Down syndrome, fragile X syndrome, tuberous sclerosis, or other genetic and chromosomal disorders.
- Almost half (about 44%) of children identified with ASD has average to above average intellectual ability.
- Children born to older parents are at a higher risk for having ASD.
A small percentage of children who are born prematurely or with low birth weight are at greater risk for having ASD.
- ASD commonly co-occurs with other developmental, psychiatric, neurologic, chromosomal, and genetic diagnoses. The co-occurrence of one or more non-ASD developmental diagnoses is 83%. The co-occurrence of one or more psychiatric diagnoses is 10%.
- Research has shown that a diagnosis of autism at age 2 can be reliable, valid, and stable.
- Even though ASD can be diagnosed as early as age 2 years, most children are not diagnosed with ASD until after age 4 years. The median age of first diagnosis by subtype is as follows.
- Autistic disorder: 3 years, 10 months
- Pervasive developmental disorder-not otherwise specified (PDD-NOS): 4 years, 1 month
- Asperger disorder: 6 years, 2 months
- Studies have shown that parents of children with ASD notice a developmental problem before their child’s first birthday. Concerns about vision and hearing were more often reported in the first year, and differences in social, communication, and fine motor skills were evident from 6 months of age.
- The total costs per year for children with ASD in the United States were estimated to be between $11.5 billion – $60.9 billion (2011 US dollars). This significant economic burden represents a variety of direct and in-direct costs, from medical care to special education to lost parental productivity.
- Children and adolescents with ASD had average medical expenditures that exceeded those without ASD by $4,110–$6,200 per year. On average, medical expenditures for children and adolescents with ASD were 4.1–6.2 times greater than for those without ASD. Differences in median expenditures ranged from $2,240 to $3,360 per year with median expenditures 8.4–9.5 times greater.
- In 2005, the average annual medical costs for Medicaid-enrolled children with ASD were $10,709 per child, which was about six times higher than costs for children without ASD ($1,812).
- In addition to medical costs, intensive behavioral interventions for children with ASD cost $40,000 to