Enhancing the development of low-birthweight, premature infants: changes in cognition and behavior over the first three years.

The Infant Health and Development Program is a randomized clinical trial to test the efficacy of educational and family support services and pediatric follow-up offered in the first 3 years of life on reducing the incidence of developmental delay in low-birthweight (LBW), preterm infants in 8 clinical sites (N = 985). Effects of the intervention on cognitive and behavior problem scores over the 3 years are examined. Significant intervention effects were seen on cognitive scores at 24 and 36 but not 12 months of age; effect sizes were similar at both ages. These effects persist when controlling for earlier cognitive scores. At 24 and 36 months, behavior problem scores for the intervention group were significantly lower than for the follow-up group; the intervention was more efficacious for children with higher initial behavior problem scores. Results are discussed in terms of timing and targeting of services for LBW and disadvantaged children.