RESUMEN
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 during the first 3 years of life, in reducing the incidence of developmental delay in low birth weight preterm infants at eight clinical sites (N = 985). It was hypothesized that larger intervention effects would be found for the domains in which low birth weight preterm infants are known to have problems, specifically visual-motor and spatial skills and receptive language skills. These analyses explore the effects of the Infant Health and Development Program on different domains of cognitive functioning. Cognitive domains are identified by means of factor analysis of the intelligence tests used at 12, 24, and 36 months (Bayley Scales of Infant Development (including the Mental and Motor scales) at 12 and 24 months; the Stanford-Binet, Peabody Picture Vocabulary Test, and Beery Test of Visual Motor Intergration at 36 months). Our results reveal that, although intervention benefits accrue across cognitive domains at 24 and 36 months, gains are most pronounced for receptive language and visual-motor and spatial skills.