title: Brief report: validity of Finnish registry-based diagnoses of autism with the ADI-R.
abstract: OBJECTIVE
  The aim of the study was to explore the validity of registry-based diagnoses of autism in Finland using the Autism Diagnostic Interview - Revised (ADI-R). This study was designed for the Finnish Prenatal Study of Autism and Autism Spectrum Disorders (FIPS-A), an ongoing research project where registry-based diagnoses will be used for epidemiological studies.
  
  
  METHODS
  In this small pilot study, a clinical sample of 95 subjects diagnosed with childhood autism or pervasive developmental disorder/pervasive developmental disorder - not otherwise specified (PDD/PDD-NOS) or Asperger's syndrome according to the Finnish Hospital Discharge Register (FHDR) was gathered nationwide. A small control group consisting of siblings without any registered diagnoses of those being examined was also included in the study. Diagnoses were further re-evaluated by interviewing parents with the ADI-R.
  
  
  RESULTS
  The mean scores of autistic subjects clearly exceeded cut-off limits for autism on all three ADI-R domains and 96% of the subjects with registered diagnosis of childhood autism fulfilled the criteria based on the instrument as well.
  
  
  CONCLUSIONS
  These results suggest that the validity of Finnish registry-based diagnoses of childhood autism can be considered good. Our findings lay important groundwork for further population- based studies of the aetiology of autism.
authors.affiliation: Department of Child Psychiatry, University of Turku, Turku, Finland. katja.lampi@utu.fi
authors.forename: K M
authors.initials: KM
authors.lastname: Lampi
authors.forename: A
authors.initials: A
authors.lastname: Sourander
authors.forename: M
authors.initials: M
authors.lastname: Gissler
authors.forename: S
authors.initials: S
authors.lastname: Niemelä
authors.forename: K
authors.initials: K
authors.lastname: Rehnström
authors.forename: E
authors.initials: E
authors.lastname: Pulkkinen
authors.forename: L
authors.initials: L
authors.lastname: Peltonen
authors.forename: L
authors.initials: L
authors.lastname: Von Wendt
mesh_terms: D020817:Asperger Syndrome / Q000175:diagnosis / Q000453:epidemiology; D001321:Autistic Disorder / Q000175:diagnosis* / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000175:diagnosis* / Q000453:epidemiology; D005387:Finland; D006801:Humans; D007406:Interview, Psychological; D010865:Pilot Projects; D012042:Registries / Q000706:statistics & numerical data; D015203:Reproducibility of Results