Abstract
Birth records of 97 children assessed at 18 months and found to be developmentally delayed were scored according to the optimality concept developed by Prechtl. These children were compared to a control series of 81 children. In order to evaluate the predictive validity of the parental developmental assessments performed at 18 months the children had been screened for school achievement problems at the age of eight years, yielding a distribution of true and false positives and true and false negatives. Rates of reduced optimality were compared to investigate firstly, the relationship between reduced optimality and developmental delay at 18 months and secondly, whether the follow-up distribution of true and false positives at eight years could be related to reduced optimality. The overall relationship between reduced optimality and developmental delay at 18 months and reduced optimality and school achievement problems at eight years was also investigated.
The 15 low scoring cases registered as mentally retarded differed significantly from controls on total mean reduced optimality. Retarded and non-retarded low-scorers differed significantly on post partum sub-scores only. When the eight-year follow-up groups were compared both retarded and non-retarded true positives differed significantly from true negatives on total mean reduced optimality. The difference in post-partum reduced optimality between retarded and all other follow-up groups but non-retarded true positives reached statistical significance. The results of the analyses of both 18-months and eight-year follow-up samples indicated that twin-birth, non-optimal birthweight and items included in the post partum index were of special significance when assessing the relative importance of events for delayed development at 18 months, school achievement problems at eight years and mental retardation. Regression analyses showed that the predictive values of reduced optimality for 18 months developmental status, school achievement problems and mental retardation at eight years were significant but low.
Key words
Case-control study - Mental retardation - Optimality - Pre- and perinatal period - School achievement problems
