Early identification and prognosis: parental developmental assessment of 18-month-old children

The overall purpose of the study was to develop a screening instrument for the identification of developmental delay which could be administered entirely by parents. Reliability, concurrent and predictive validity was investigated in a Swedish population of 3,245 18-month-old children. The prevalence of mental retardation and learning disabilities implied by educational support provided in the regular school system was investigated in follow-up studies at 8 and 14 years. At 8 years, 20 children were administratively classified as mentally retarded. At 18 months they were among lowscorers or attrition cases. Among the remaining lowscorers 51.2% at 8 years and 26.6% at 14 years received special education in the normal school, i.e. were true positives. The rates of false negatives, i.e. children scoring normally at 18 months who received special education at 8 and 14 years, were 18.5% and 4.6% respectively. The prevalence of administratively classified mentally retarded was 0.62% at 8 years and 0.65% at 14 years. When the cases receiving special education in regular classes were added the prevalence figures were 2.1% at 8 years and 1.29% at 14 years. Apart from showing that parants can and will fill out a questionnaire on the developmental progress of their children that can be used for predictive purposes the study also points at the relatively inherent in the concept of mental retardation and true prevalence of especially mild mental retardation.