title: Autism spectrum disorders and health care expenditures:  the effects of co-occurring conditions.
abstract: OBJECTIVE
  Children with autism spectrum disorders (ASDs) often have co-occurring conditions, but little is known on the effect of those conditions on their medical care cost. Medical expenditures attributable to ASDs among Medicaid-enrolled children were calculated, and the effects of 3 commonly co-occurring conditions--intellectual disability (ID), attention deficit/hyperactivity disorder (ADHD), and epilepsy-on those expenditures were analyzed.
  
  
  METHODS
  Using MarketScan Medicaid Multi-State Databases (2003-2005) and the International Classification of Disease, Ninth Revision, children with ASD were identified. Children without ASD formed the comparison group. The 3 co-occurring conditions were identified among both the ASD and the comparison groups. Annual mean, median, and 95th percentile of total expenditures were calculated for children with ASD and the co-occurring conditions and compared with those of children without ASD. Multivariate analyses established the influence of each of those co-occurring conditions on the average expenditures for children with and without ASD.
  
  
  RESULTS
  In 2005, 47% of children with ASD had at least 1 selected co-occurring condition; attention deficit/hyperactivity disorder was the most common, at 30%. The mean medical expenditures for children with ASD were 6 times higher than those of the comparison group. Children with ASD and ID incurred expenditures 2.7 times higher than did children with ASD and no co-occurring condition.
  
  
  CONCLUSIONS
  Medicaid-enrolled children with ASD incurred higher medical costs than did Medicaid-enrolled children without ASD. Among Medicaid-enrolled children with ASD, cost varied substantially based on the presence of another neurodevelopmental disorder. In particular, children with ID had much higher costs than did other children with ASD.
authors.affiliation: National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA. gpeacock@cdc.gov
authors.forename: Georgina
authors.initials: G
authors.lastname: Peacock
authors.forename: Djesika
authors.initials: D
authors.lastname: Amendah
authors.forename: Lijing
authors.initials: L
authors.lastname: Ouyang
authors.forename: Scott D
authors.initials: SD
authors.lastname: Grosse
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000191:economics / Q000453:epidemiology; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000150:complications* / Q000191:economics* / Q000453:epidemiology; D002675:Child, Preschool; D015897:Comorbidity; D004827:Epilepsy / Q000150:complications / Q000191:economics / Q000453:epidemiology; D005260:Female; D005102:Health Expenditures / Q000145:classification; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000150:complications / Q000191:economics / Q000453:epidemiology; D008297:Male; D008484:Medicaid / Q000191:economics; D012042:Registries; D014481:United States / Q000453:epidemiology