Can the Bayley Scales of Infant Development at 18 months predict child behaviour at 7 years?

Aim: Infants born preterm (<37 weeks' gestation) are at risk of poor neurodevelopmental outcomes; hence, many neonatal centres routinely follow up infants using the Bayley Scales of Infant Development (BSID), although the predictive validity of the BSID for children born preterm is questionable. Our objective is to evaluate the predictive capacity of the BSID for behavioural functioning at school age of children born preterm.

Methods: Children (n = 657 children born <33 weeks' gestation) were enrolled at birth from five neonatal centres around Australia. A psychologist assessed child development at 18 months using the BSID-II. When children were 7 years (corrected age) of age, parents completed the Strengths and Difficulties Questionnaire, the Behavior Rating Inventory of Executive Function and the Conners 3rd Edition Attention Deficit Hyperactivity Disorder Index. We explored associations between BSID-II at 18 months and behaviour scores at 7 years and examined the interaction effect of the use of an allied health service between the BSID-II and behaviour assessments.

Results: For every one-point increase on the BSID-II Mental Development Index, behaviour scores decreased by 0.07 points for the Strengths and Difficulties Questionnaire Total Difficulties (95% confidence interval (CI) -0.10, -0.03), 0.12 points for the Behavior Rating Inventory of Executive Function Global Executive Composite (95% CI -0.21, -0.04) and 0.16 points for the Conners 3rd Edition Attention Deficit Hyperactivity Disorder Index (95% CI -0.26, -0.05).

Conclusion: The BSID-II at 18 months was weakly associated with parent-reported behaviour at 7 years in children born preterm.