Predictors of developmental delay at 18 months and later school achievement problems.

The aim of the study was to examine the predictive value of the variables of parental assessment score, pre-, peri-, and postpartum optimality, sex, socioeconomic status (SES), and maternal education with respect to developmental delay at 18 months, and intellectual disability and school achievement problems at 8 and 14 years. The sample studied comprised 101 children (53 low scorers and 48 controls) originally from a total population of 2783 children assessed by their parents at 18 months using a screening instrument. Data were analysed by logistic regression. The results yielded moderate but statistically significant correlations between predictor and outcome variables. Optimality score and maternal education were the best predictors of developmental delay at 18 months. At 8 years, parental assessment score and maternal education constituted the best predictors of school achievement problems. At 14 years, SES together with parental assessment score were included in the model, when school achievement problems were predicted. Parental assessment score showed the strongest association with school achievement problems at both 8 and 14 years, when children with intellectual disability were included in the analysis. The exclusion of children with intellectual disability from the analyses yielded a stronger association between maternal education (at 8 years) and SES (at 14 years) and school achievement problems. The overall classification accuracy of the models varied between 67% and 88%. Specificity varied from 65% at 18 months to 95% at 14 years. Sensitivity varied from 70% at 18 months and 55% (all cases) and 42% (children with intellectual disability excluded) at 14 years.