Identifying at-risk children for early intervention services: lessons from the Infant Health and Development Program

A U.S. law mandates early intervention services for infants and young children who have, or are at risk for, developmental problems. Participating states must develop definitions for identifying infants and young children at risk for developmental problems. To assess the sensitivity, specificity, and positive predictive value of some commonly identified risk factors, we examined the definitions proposed by five states. Data on risk factors and 36-month developmental outcomes were obtained from follow-up participants in the Infant Health and Development Program, a multisite, collaborative prospective intervention program involving 985 low birth weight preterm infants. Few individual risk factors proposed by these states were associated with poor developmental outcomes. Characteristics with positive predictive values greater than 30% were highly specific but tended to involve few cases. Risk factors with positive predictive values greater than 50%, such as hypothyroidism, occurred infrequently (< 6%) in this sample. When state definitions for at-risk children were examined in composite, each definition yielded a positive predictive value of 25% to 35%, with poor specificities ranging from 12% to 40%. These data on low birth weight infants have implications for the design and funding of population-based early intervention programs, and suggest that more careful clinical and longitudinal research is necessary before appropriate definitions can be promulgated for identifying children in need of early intervention services.