Severe mental retardation among children in the county of Arhus, Denmark. A community study on prevalence and provision of service.

An epidemiological census investigation on severe mental retardation among children under 15 years were carried out on July 1, 1970, in the community of Aarhus. Case finding procedures are described in detail. One hundred and seventy-one severely retarded children were found in total population of 233,162 with 50,667 children under 15 years. The age-specific prevalence rate was 3.38 per 1,000. About 20% of the severely retarded children are not registered in the Danish National Mental Retardation Service when they reached school age. One third of the children are under residental care, but only half of these are in subnormality hospitals while the other half reside in waiting homes. Among 64% living at home, two thirds receive day-care or training. Comparisons are made especially with two other prevalence surveys, one covering the same area, and the other identical in methods.