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Sustained effects of high participation in an early intervention for low-birth-weight premature infants
Jennifer L Hill1, Jeanne Brooks-Gunn2, Jane Waldfogel3
1School of International and Public Affairs.
Insights
High-quality early childhood education significantly boosts cognitive development in low-birth-weight infants. Intensive participation in programs like the Infant Health and Development Program (IHDP) showed substantial long-term intelligence gains.
Area of Science:
- Developmental Psychology
- Pediatric Health
- Early Childhood Education
Background:
- The Infant Health and Development Program (IHDP) was an 8-site randomized trial involving 1,082 low-birth-weight (LBW) premature infants.
- The program provided high-quality, center-based care for 2nd and 3rd year olds, including full-day, 50-week per year services.
Purpose of the Study:
- To estimate the high-dosage effects of intensive participation in the IHDP on cognitive outcomes.
- To compare these high-dosage effect estimates with traditional intention-to-treat (ITT) estimates.
Main Methods:
- A new methodology was employed to identify a matched comparison group within the IHDP follow-up cohort for children with high participation rates (>400 days).
- Cognitive outcomes were assessed using the Wechsler Intelligence Scale for Children (WISC) Full and Verbal scales at age 8.
- ITT analyses were also conducted for comparison.
Main Results:
- Children attending >400 days showed WISC score increases of 7–10 points.
- Heavier LBW infants (2,001–2,500 g) with high participation experienced approximately 14-point gains.
- Lighter LBW infants (< or = 2,000 g) with high participation showed gains of about 8 points, all substantially higher than ITT estimates.
Conclusions:
- Intensive, high-quality early childhood education yields significant cognitive benefits for low-birth-weight infants.
- The positive effects are more pronounced in heavier LBW infants and increase with higher program participation.
- New methodologies for estimating high-dosage effects provide valuable insights beyond traditional ITT analyses.
Abstract:
Effects of high participation in the Infant Health and Development Program (IHDP), an 8-site randomized trial that targeted low-birth-weight (LBW) premature infants (N=1,082), were estimated. Children in the treatment group were offered high-quality center-based care in their 2nd and 3rd years of life (full-day care, 50 weeks per year). High-dosage effects were estimated with a new methodology that found a matched comparison group within the follow-up group for those with high participation rates; these estimates were compared with traditional intention-to-treat (ITT) estimates. At age 8, effects on the Wechsler Intelligence Scale for Children Full and Verbal scales for children who attended > 400 days ranged from 7 to 10 points. For the heavier LBW infants (2,001-2,500 g), the effects were about 14 points for > 400 days; for the lighter LBW infants (< or = 2,000 g), the effects were about 8 points. These effects were all substantially higher than corresponding ITT effects. Similar but smaller effects were found for children who attended > 350 days.
