title: Prevalence of Inflammatory Bowel Disease Among Patients with Autism Spectrum Disorders.
abstract: BACKGROUND
  The objective of this study was to measure the prevalence of inflammatory bowel disease (IBD) among patients with autism spectrum disorders (ASD), which has not been well described previously.
  
  
  METHODS
  The rates of IBD among patients with and without ASD were measured in 4 study populations with distinct modes of ascertainment: a health care benefits company, 2 pediatric tertiary care centers, and a national ASD repository. The rates of IBD (established through International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes) were compared with respective controls and combined using a Stouffer meta-analysis. Clinical charts were also reviewed for IBD among patients with ICD-9-CM codes for both IBD and ASD at one of the pediatric tertiary care centers. This expert-verified rate was compared with the rate in the repository study population (where IBD diagnoses were established by expert review) and in nationally reported rates for pediatric IBD.
  
  
  RESULTS
  In all of case-control study populations, the rates of IBD-related ICD-9-CM codes for patients with ASD were significantly higher than that of their respective controls (Stouffer meta-analysis, P < 0.001). Expert-verified rates of IBD among patients with ASD were 7 of 2728 patients in one study population and 16 of 7201 in a second study population. The age-adjusted prevalence of IBD among patients with ASD was higher than their respective controls and nationally reported rates of pediatric IBD.
  
  
  CONCLUSIONS
  Across each population with different kinds of ascertainment, there was a consistent and statistically significant increased prevalance of IBD in patients with ASD than their respective controls and nationally reported rates for pediatric IBD.
authors.affiliation: *School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts; †Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts; ‡Inflammatory Bowel Disease Center, Boston Children's Hospital, Boston, Massachusetts; §Wake Forest Baptist Medical Center, Winston-Salem, North Carolina; and ‖Aetna, Inc., Hartford, Connecticut.
authors.forename: Finale
authors.initials: F
authors.lastname: Doshi-Velez
authors.forename: Paul
authors.initials: P
authors.lastname: Avillach
authors.forename: Nathan
authors.initials: N
authors.lastname: Palmer
authors.forename: Athos
authors.initials: A
authors.lastname: Bousvaros
authors.forename: Yaorong
authors.initials: Y
authors.lastname: Ge
authors.forename: Kathe
authors.initials: K
authors.lastname: Fox
authors.forename: Greg
authors.initials: G
authors.lastname: Steinberg
authors.forename: Claire
authors.initials: C
authors.lastname: Spettell
authors.forename: Iver
authors.initials: I
authors.lastname: Juster
authors.forename: Isaac
authors.initials: I
authors.lastname: Kohane
mesh_terms: D000293:Adolescent; D000067877:Autism Spectrum Disorder / Q000453:epidemiology*; D016022:Case-Control Studies; D002648:Child; D015897:Comorbidity; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology*; D007348:Insurance, Health / Q000706:statistics & numerical data; D008297:Male; D015995:Prevalence; D062606:Tertiary Care Centers / Q000706:statistics & numerical data