Ascertainment of subnormality in Bedfordshire.
D000293:Adolescent; D002648:Child; D002674:Child, Institutionalized; D002675:Child, Preschool; D004314:Down Syndrome / Q000453:epidemiology*; D004739:England; D006760:Hospitalization; D006801:Humans; D008607:Intellectual Disability / Q000453:epidemiology*; D012424:Rural Population