Nine-year outcome of the Vermont intervention program for low birth weight infants.

Twenty-four low birth weight children who had received an experimental intervention (LBWE) during the neonatal period, 31 control children who had received no treatment (LBWC), and 36 normal birth weight children were compared. The intervention involved seven hospital sessions and four home sessions in which a nurse helped mothers adapt to their LBW babies. At age 9, LBWE children scored significantly higher than LBWC children on the Kaufman Mental Processing Composite, Sequential, Simultaneous, Achievement, Arithmetic, and Riddles scales, after statistical adjustments for socioeconomic status. The LBWE children had also advanced more rapidly in school than had LBWC children. Parent (Child Behavior Checklist) and teacher (Teacher's Report Form) ratings of school functioning were more favorable for LBWE than LBWC children, with especially strong effects on Teacher's Report Form scores for academic performance and the attention problems syndrome. At age 9, LBWE children were not significantly inferior to normal birth weight children on any measure. These results bear out a progressive divergence between the LBWE and LBWC children that first became statistically significant in cognitive scores at age 3. The findings suggest that the intervention prevented cognitive lags among LBW children and that this eventually had a favorable effect on academic achievement, behavior, and advancement in school. The progression from no significant differences between LBWE and LBWC children on early cognitive and achievement scores to significant and pervasive differences in later functioning argues for long-term follow-up periods to evaluate properly the power of behavioral interventions to compensate for biological risks.