Background and Aims The Bayley Scales of Infant Development (BSID) is the most widely used measure to assess neurodevelopment of very preterm (gestational age ≤32 weeks) and very low birth weight (VLBW, ≤1500grams) infants in the first three years of life. This meta-analysis determines the predictive value of the mental subscale (MDI) and motor subscale (PDI) of the BSID for later (≥36 months) motor and cognitive development in very preterm/VLBW children.
Methods PubMed, PsychINFO and CINAHL were searched for English-language peer-reviewed studies published before April 2012. Studies were included if they reported odds ratios or correlations between the MDI/PDI scores obtained in the first three years of life, and standardized intelligence or motor assessment in childhood (≥36 months of age). Meta-analytic methods were applied to aggregate available data.
Results A total of 16 studies met inclusion criteria. Across 15 studies encompassing 1335 very preterm/VLBW children, MDI scores were strongly predictive for later cognitive development, r=0.61 (95%CI: 0.57–0.64), p<0.001. The relationship between MDI scores and later cognitive development was not mediated by birth weight (p=0.56), gestational age (p=.70), and time interval between assessments (p=0.55). Across four studies including 465 very preterm/VLBW children, PDI scores were moderately predictive for later motor function, r=0.32 (95%CI: 0.22–0.40), p<0.001.
Conclusions In very preterm/VBLW children, MDI scores explain 37% of the variance in later cognitive functioning, whereas PDI scores explain 10% of later motor development. Thus a large proportion of the variance remains unexplained, underlining the importance of enhancing prediction of developmental outcomes.