title: The prevalence of severe mental handicap in Northern Ireland.
abstract: There are four administrative areas (Health and Social Services Boards) in Northern Ireland. Two prevalence surveys, carried out several years apart, show that there is a significant geographical gradient in the rates of severe mental handicap (IQ less than 50). The rates in the 20-29-year-old groups in the Eastern and Northern Boards range between 4.07 and 4.82 per thousand; comparable rates in the Southern and Western Boards range between 5.17 and 6.37. A similar gradient was discernible in the distribution of Down's syndrome.
authors.affiliation: Department of Finance and Personnel, Belfast, Northern Ireland.
authors.forename: J R
authors.initials: JR
authors.lastname: Mallon
authors.forename: D N
authors.initials: DN
authors.lastname: MacKay
authors.forename: G
authors.initials: G
authors.lastname: McDonald
authors.forename: R
authors.initials: R
authors.lastname: Wilson
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D004314:Down Syndrome / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008607:Intellectual Disability / Q000453:epidemiology*; D008297:Male; D009660:Northern Ireland / Q000453:epidemiology