Internal medicine

Pediatrics

Cohort study

Population

Psychiatry

Cognition

Intelligence quotient

Prospective cohort study

Multivariate analysis

Receiver operating characteristic

Cohort

Wechsler Preschool and Primary Scale of Intelligence

Medicine

Wechsler Intelligence Scale for Children

Wechsler Adult Intelligence Scale

Environmental health

PEDIATRICS

OBJECTIVES: To assess the predictive value of the 36-month Ages &amp; Stages Questionnaire (ASQ) score for IQ score at age 5 to 6 years in the general population and to identify factors associated with IQ &amp;lt;85 once the ASQ score is taken into account. METHODS: Data were collected from 939 children enrolled in a population-based prospective cohort study. Developmental outcomes at 36 months were assessed via the ASQ and at 5 to 6 years via the Wechsler Preschool and Primary Scale of Intelligence. The ASQ threshold was identified via the receiver operating characteristic curve. Additional predictive factors to obtain an IQ &amp;lt;85 were investigated, and their interaction with ASQ score was studied. RESULTS: Sixty-nine children (7.3%) had an IQ &amp;lt;85. A 36-month ASQ score threshold of 270 was optimal to identify children with an IQ &amp;lt;85 at 5 to 6 years, with a 0.77 ± 0.11 sensitivity and 0.68 ± 0.03 specificity. Maternal educational level and occupational activity at the time of ASQ completion were associated with the risk of an IQ &amp;lt;85 at a given ASQ level. In the multivariate model, no interaction between the studied factors and ASQ score reached significance. CONCLUSIONS: In the general pediatric population, 36-month ASQ parental reports could be used to identify children at later risk of cognitive delay. Low maternal education level should also be considered as a major risk factor for lower IQ in preschool children regardless of ASQ score.

Ages and Stages Questionnaire at 3 Years for Predicting IQ at 5–6 Years