“At corrected age 36 months, the intervention group had significantly higher mean IQ scores than the follow-up group (mean difference in the heavier group was 13.2 and in the lighter group 6.6), significantly fewer maternally reported behavior problems, and a small, but statistically significant, increase in maternally reported minor illnesses for the lighter-birth-weight group only, with no difference in serious health conditions.”

“Cognitive development scores were 7.2 points higher (p=0.002) in the intervention (INT) group, after adjustment for baseline differences in site, sociodemographic characteristics, and neonatal morbidity, and were 9.4 points higher (p<0.003) when the 29 children with significant cerebral palsy were removed. No differences in behavior, serious morbidity, functional status, or health rating were found overall. The infants in the INT group who weighed <1000 grams at birth had significantly lower behavior problem scores but no differences on other outcomes. All children in the INT group had slightly higher rates of less serious morbidity.”

“At age 5 years, the intervention group had full-scale IQ scores similar to children in the follow-up only group. However, in the heavier LBW stratum, children in the intervention group had higher full-scale IQ scores (3.7 points higher; p=.03) and higher verbal IQ scores (4.2 points higher; p=.02). No significant differences between intervention and follow-up only groups in cognitive measures at age 5 years were noted in the lighter LBW infants. The intervention and follow-up groups were similar in behavior and health measures regardless of LBW stratum.”

“At age 8 years, in the entire cohort and in the lighter LBW stratum, the intervention and follow-up only groups were similar on all primary outcomes measures. Differences favoring the intervention group were found within the heavier LBW group: full-scale IQ score (4.4 points higher; p=.007), verbal IQ score (4.2 points higher; p=.01), performance IQ score (3.9 points higher; p=.02), mathematics achievement score (4.8 points higher; p=.04), and receptive vocabulary score (6.7 points higher; p=.001). On a physical functioning subscale, the whole intervention group received less favorable ratings, while the lighter LBW intervention group had lower maternal ratings assessing social limitations caused by behavior.”