title: Demographic profile of families and children in the Study to Explore Early Development (SEED): Case-control study of autism spectrum disorder.
abstract: The Study to Explore Early Development (SEED) is designed to enhance knowledge of autism spectrum disorder characteristics and etiologies.
  
  
  
  This paper describes the demographic profile of enrolled families and examines sociodemographic differences between children with autism spectrum disorder and children with other developmental problems or who are typically developing.
  
  
  
  This multi-site case-control study used health, education, and birth certificate records to identify and enroll children aged 2-5 years into one of three groups: 1) cases (children with autism spectrum disorder), 2) developmental delay or disorder controls, or 3) general population controls. Study group classification was based on sampling source, prior diagnoses, and study screening tests and developmental evaluations. The child's primary caregiver provided demographic characteristics through a telephone (or occasionally face-to-face) interview. Groups were compared using ANOVA, chi-squared test, or multinomial logistic regression as appropriate.
  
  
  
  Of 2768 study children, sizeable proportions were born to mothers of non-White race (31.7%), Hispanic ethnicity (11.4%), and foreign birth (17.6%); 33.0% of households had incomes below the US median. The autism spectrum disorder and population control groups differed significantly on nearly all sociodemographic parameters. In contrast, the autism spectrum disorder and developmental delay or disorder groups had generally similar sociodemographic characteristics.
  
  
  
  SEED enrolled a sociodemographically diverse sample, which will allow further, in-depth exploration of sociodemographic differences between study groups and provide novel opportunities to explore sociodemographic influences on etiologic risk factor associations with autism spectrum disorder and phenotypic subtypes.
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, Campus Box B119, 13001 E. 17th Place, Aurora, CO 80045, USA. Electronic address: Carolyn.DiGuiseppi@ucdenver.edu.
authors.forename: Carolyn G
authors.initials: CG
authors.lastname: DiGuiseppi
authors.affiliation: Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB #7435, Chapel Hill, NC 27599-7435, USA.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Daniels
authors.affiliation: Wendy Klag Center for Autism and Developmental Disabilities, Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, 624 N. Broadway, HH 850, Baltimore, MD 21205, USA.
authors.forename: Daniele M
authors.initials: DM
authors.lastname: Fallin
authors.affiliation: Department of Psychiatry, University of Colorado School of Medicine, Campus Box F546, 13001 E. 17th Place, Aurora, CO 80045, USA.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Rosenberg
authors.affiliation: National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Schieve
authors.affiliation: Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill, 725 Martin Luther King Jr. Blvd., CB#7590, Chapel Hill, NC 27599-7590, USA.
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Thomas
authors.affiliation: California Department of Public Health, 850 Marina Bay Pkwy, Bldg. P/EHIB, Richmond, CA 94804, USA.
authors.forename: Gayle C
authors.initials: GC
authors.lastname: Windham
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, Campus Box B119, 13001 E. 17th Place, Aurora, CO 80045, USA.
authors.forename: Cynthia W
authors.initials: CW
authors.lastname: Goss
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, Campus Box B119, 13001 E. 17th Place, Aurora, CO 80045, USA.
authors.forename: Gnakub N
authors.initials: GN
authors.lastname: Soke
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, Campus Box B119, 13001 E. 17th Place, Aurora, CO 80045, USA.
authors.forename: Dustin W
authors.initials: DW
authors.lastname: Currie
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA.
authors.forename: Alison B
authors.initials: AB
authors.lastname: Singer
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA.
authors.forename: Li-Ching
authors.initials: LC
authors.lastname: Lee
authors.affiliation: Kaiser Permanente, ASD Center, Department of Psychiatry, 6620 Via del Oro, San Jose, CA 95119, USA.
authors.forename: Pilar
authors.initials: P
authors.lastname: Bernal
authors.affiliation: Autism Research Program, Kaiser Permanente Division of Research, 2000 Broadway, Oakland, CA 94612, USA.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Croen
authors.affiliation: Division of Disease Control and Environmental Epidemiology, Colorado Department of Public Health and Environment, 4300 Cherry Creek Drive South, Denver, CO 80246-1530, USA.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Miller
authors.affiliation: Center for Autism and Developmental Disabilities, Research and Epidemiology (CADDRE), University of Pennsylvania, School of Nursing, 418 Curie Blvd, Claire Fagan Hall, Philadelphia, PA 19104, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Pinto-Martin
authors.affiliation: Center for Autism and Developmental Disabilities, Research and Epidemiology (CADDRE), University of Pennsylvania, School of Nursing, 418 Curie Blvd, Claire Fagan Hall, Philadelphia, PA 19104, USA.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Young
authors.affiliation: National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA.
authors.forename: Diana E
authors.initials: DE
authors.lastname: Schendel
mesh_terms: D000293:Adolescent; D000328:Adult; D000067877:Autism Spectrum Disorder / Q000453:epidemiology*; D001321:Autistic Disorder / Q000453:epidemiology; D017028:Caregivers; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002658:Developmental Disabilities / Q000453:epidemiology; D006233:Persons with Disabilities; D005006:Ethnicity; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007182:Income; D007223:Infant; D016015:Logistic Models; D008297:Male; D044469:Racial Groups; D012923:Social Class; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
keywords: Autism spectrum disorder; Demographics; Epidemiology; Socioeconomic factors