Autism in Northern Finland, A prevalence, follow-up and descriptive study of children and adolescents with autistic disorder

Abstract

Objectives. The aims of this study were to estimate the prevalence of autism in Northern Finland and to assess retro-spectively the associations of autistic disorder with identified medical conditions and additional disabilities in this defined population of children and adolescents with autistic disorder. In order to find out the factors influencing the outcome, the methods of treatment/habilitation and the interventions used were studied in detail. The last aim was to elicit reliable in-formation for decision-makers as well as ideas for giving sup-port and, because of the presumed better outcome, saving re-sources in the long run. Methods. The data were collected from hospital records and the records of the central institutions for the intellectually dis-abled in the Provinces of Oulu and Lapland in 1996-1997. Results. The age-specific prevalences obtained in this study showed the prevalence to be lowest, i.e. 6.1 per 10 000, in the oldest age group of 15-to 18-year-old adolescents and high-est, i.e. 20.7 per 10 000, in the age group of 5-to 7-year-old children, when the criteria of ICD-10 and DSM-IV were used. In this study, almost 50% of the autistic cases had a tested IQ above 70. Associated medical disorders or associated disor-ders of known or suspected genetic origin were diagnosed in 12.3 %. Other associated medical disorders were epilepsy, hy-drocephalus, fetal alcohol syndrome and cerebral palsy. Se-vere impairment of vision was evident in 3.7 %. The most common therapies were physiotherapy and speech, occupa-tional and music therapy. 43.9 % of the children and adoles-cents with autism received specific training according to the