title: European studies on prevalence and risk of autism spectrum disorders according to immigrant status-a review.
abstract: BACKGROUND
  Autism spectrum disorders (ASDs), once considered to be rare, are now reaching prevalence estimates of 1% and higher. Studies conducted in North America indicate large racial/ethnic disparities in the diagnosis of ASDs. Others show, that immigrant children have similar prevalence rates of ASDs as native children, although they are diagnosed later compared with native children. In relation to a EU funded network action, Enhancing the Scientific Study of Early Autism, it was considered important to review the literature on this subject.
  
  
  METHODS
  A comprehensive literature search was undertaken for original articles reporting on prevalence and risk for ASD in Europe among immigrants and ethnic minorities and data across studies were compared.
  
  
  RESULTS
  Seventeen studies conducted in Europe concerning immigrants and ethnic minorities were found. Fifteen studies suggest a higher prevalence rate of ASDs among children of immigrants in comparison to native children (RR = 1.02-1.74; OR = 0.6-10.5). One study revealed higher prevalence of autism (OR = 2.2; 95% CI 1.6-3.1) and lower prevalence of Asperger syndrome in immigrants (OR = 0.6; 95% CI 0.3-0.97). One study showed a lower prevalence of Asperger syndrome in immigrants (aOR = 0.1, 95% CI 0.01-0.5). The majority of those analyses involved immigrants from outside Europe, e.g. from Africa and South America.
  
  
  CONCLUSIONS
  After analysing the results of studies conducted in Europe, it is unclear if higher prevalence estimates of ASDs among immigrants in this region reflect true differences, especially considering many potential confounding factors, e.g. genetic, biological, environmental and cultural. Considering the number of people migrating within Europe there is a substantial need to study further the prevalence of ASDs in immigrant groups.
authors.affiliation: Polish Academy of Sciences, ul. Jaracza 1, Warszawa 00-378, Poland.
authors.forename: Rafal
authors.initials: R
authors.lastname: Kawa
authors.affiliation: The State Diagnostic and Counselling Centre, Digranesvegur 5, 200 Kópavogur, Iceland.|Faculty of Medicine, University of Iceland, Reykjavík, Iceland.
authors.forename: Evald
authors.initials: E
authors.lastname: Saemundsen
authors.affiliation: The State Diagnostic and Counselling Centre, Digranesvegur 5, 200 Kópavogur, Iceland.
authors.forename: Sigrídur
authors.initials: S
authors.lastname: Lóa Jónsdóttir
authors.affiliation: Department of Special Education, Centre for Cognitive and Motor Disabilities, Utrecht University, Utrecht, Netherlands.
authors.forename: Annika
authors.initials: A
authors.lastname: Hellendoorn
authors.affiliation: Aarhus University Hospital, Centre for Child and Adolescent Psychiatry, Denmark.
authors.forename: Sanne
authors.initials: S
authors.lastname: Lemcke
authors.affiliation: INICO, Faculty of Education, University of Salamanca, Spain.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Canal-Bedia
authors.affiliation: Rare Diseases Research Insititute, National Institue of Health Carlos III, Madrid, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: García-Primo
authors.affiliation: Department of Child Psychiatry, Oulu University Hospital, Finland.|PEDEGO Research Unit, Child Psychiatry, University of Oulu, Finland.
authors.forename: Irma
authors.initials: I
authors.lastname: Moilanen
mesh_terms: D000067877:Autism Spectrum Disorder / Q000175:diagnosis* / Q000453:epidemiology* / Q000208:ethnology; D002675:Child, Preschool; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D011159:Population Surveillance; D015995:Prevalence