Data & Statistics

Prevalence

• About 1 in 88 children has been identified with an autism spectrum disorder (ASD) according to estimates from CDC's Autism and Developmental Disabilities Monitoring (ADDM) Network. [Read article] 
• ASDs are reported to occur in all racial, ethnic, and socioeconomic groups. [Read article]
• ASDs are almost 5 times more common among boys (1 in 54) than among girls (1 in 252). [Read article]
• Studies in Asia, Europe, and North America have identified individuals with an ASD with an average prevalence of about 1%. A recent study in South Korea reported a prevalence of 2.6%. [Data table] [Read article]
• About 1 in 6 children in the U.S. had a developmental disability in 2006-2008, ranging from mild disabilities such as speech and language impairments to serious developmental disabilities, such as intellectual disabilities, cerebral palsy, and autism.  [Read summary]

 

 

Learn more about prevalence of ASDs »

Learn more about the ADDM Network »

Learn more about MADDSP »

 

Risk Factors and Characteristics

• Studies have shown that among identical twins, if one child has an ASD, then the other will be affected about 36-95% of the time. In non-identical twins, if one child has an ASD, then the other is affected about 0-31% of the time. ^[1-4]
• Parents who have a child with an ASD have a 2%–18% chance of having a second child who is also affected.^[5,6]
• ASDs tend 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, and other genetic and chromosomal disorders.^[7-10]
• The majority (62%) of children the ADDM Network identified as having ASDs did not have intellectual disability (intelligence quotient <=70). [Read article]

Most recent intelligence quotient (IQ) as of age 8 years among children identified with autism spectrum disorders (ASDs) for whom psychometric test data were available,* by site and sex- Autism and Developmental Disabilities Monitoring Network, seven sites†, United States, 2008

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• Children born to older parents are at a higher risk for ASDs. [Read summary]
• A small percentage of children who are born prematurely or with low birth weight are at greater risk for having ASDs. [Read summary]
• 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%. [Read summary]

 

Diagnosis

• Research has shown that a diagnosis of autism at age 2 can be reliable, valid, and stable.  [Read summary] [Read summary]
• More children are being diagnosed at earlier ages—a growing number (18%) of them by age 3. Still, most children are not diagnosed until after they reach age 4. Diagnosis is a bit earlier for children with autistic disorder (4 years) than for children with the more broadly-defined autism spectrum diagnoses (4 years, 5 months), and diagnosis is much later for children with Asperger Disorder (6 years, 3 months). [Read article]
• Studies have shown that parents of children with ASDs 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.[Read summary] [Read summary]

 

Economic Costs

• Individuals with an ASD had average medical expenditures that exceeded those without an ASD by $4,110–$6,200 per year. On average, medical expenditures for individuals with an ASD were 4.1–6.2 times greater than for those without an ASD. Differences in median expenditures ranged from $2,240 to $3,360 per year with median expenditures 8.4–9.5 times greater. [Read article]
• In 2005, the average annual medical costs for Medicaid-enrolled children with an ASD were $10,709 per child, which was about six times higher than costs for children without an ASD ($1,812). [Read summary]
• In addition to medical costs, intensive behavioral interventions for children with ASDs cost $40,000 to $60,000 per child per year.^[11]

 

 

References

1. Rosenberg RE, Law JK, Yenokyan G, McGready J, Kaufmann WE, Law PA. Characterisitics and concordance of autism spectrum disorders among 277 twin pairs. Arch Pediatr Adolesc Med. 2009; 163(10): 907-914.
2. Hallmayer J, Cleveland S, Torres A, Phillips J, Cohen B, Torigoe T, Miller J, Fedele A, Collins J, Smith K, Lotspeich L, Croen LA, Ozonoff S, Lajonchere C, Grether JK, Risch N. Genetic heritability and shared environmental factors among twin pairs with autism. Arch Gen Psychiatry. 2011; 68(11): 1095-1102.
3. Ronald A, Happe F, Bolton P, Butcher LM, Price TS, Wheelwright S, Baron-Cohen S, Plomin R. Genetic heterogeneity between the three components of the autism spectrum: A twin study. J. Am. Acad. Child Adolesc. Psychiatry. 2006; 45(6): 691-699.
4. Taniai H, Nishiyama T, Miyahci T, Imaeda M, Sumi S. Genetic influences on the board spectrum of autism: Study of proband-ascertained twins. Am J Med Genet B Neuropsychiatr Genet. 2008; 147B(6): 844-849.
5. Ozonoff S, Young GS, Carter A, Messinger D, Yirmiya N, Zwaigenbaum L, Bryson S, Carver LJ, Constantino JN, Dobkins K, Hutman T, Iverson JM, Landa R, Rogers SJ, Sigman M, Stone WL. Recurrence risk for autism spectrum disorders: A Baby Siblings Research Consortium study. Pediatrics. 2011; 128: e488-e495.
6. Sumi S, Taniai H, Miyachi T, Tanemura M. Sibling risk of pervasive developmental disorder estimated by means of an epidemiologic survey in Nagoya, Japan. J Hum Genet. 2006; 51: 518-522.
7. DiGuiseppi C, Hepburn S, Davis JM, Fidler DJ, Hartway S, Lee NR, Miller L, Ruttenber M, Robinson C. Screening for autism spectrum disorders in children with Down syndrome. J Dev Behav Pediatr. 2010; 31:181-191.
8. Cohen D, Pichard N, Tordjman S, Baumann C, Burglen L, Excoffier E, Lazar G, Mazet P, Pinquier C, Verloes A, Heron D. Specific genetic disorders and autism: Clinical contribution towards their identification. J Autism Dev Disord. 2005; 35(1): 103-116.
9. Hall SS, Lightbody AA, Reiss AL. Compulsive, self-injurious, and autistic behavior in children and adolescents with fragile X syndrome. Am J Ment Retard. 2008; 113(1): 44-53.
10. Zecavati N, Spence SJ. Neurometabolic disorders and dysfunction in autism spectrum disorders. Curr Neurol Neurosci Rep. 2009; 9(2): 129-136.
11. Amendah, D., Grosse, S.D., Peacock, G., & Mandell, D.S. (2011). The economic costs of autism: A review. In D. Amaral, D. Geschwind, & G. Dawson (Eds.), Autism spectrum disorders (pp. 1347-1360). Oxford: Oxford University Press.