Abstract
IMPORTANCE: National monitoring surveys indicate that developmental disabilities among US children constitute a substantial public health issue. While scientific literature documents the benefits of targeted, developmental interventions, there has been less study of formal early intervention (EI) services provided through Part C of the Individuals With Disabilities Education Act. OBJECTIVE: To assess the population-level utilization of the New York City EI program and estimate the association between receipt of EI services before 3 years of age and academic achievement later in childhood. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study was performed within an administrative data linkage of public health and educational data systems in New York City, with records from January 1, 1994, to December 31, 2007. Participants included children born in New York City between January 1, 1994, and December 31, 1998, who attended public elementary school for third grade. Analyses were conducted from January 1, 2023, to December 31, 2024. EXPOSURE: Any use of EI services from birth through 3 years of age. MAIN OUTCOMES AND MEASURES: The primary outcomes were standardized test scores in math and English language arts (ELA) in third grade. After propensity score matching, linear and log-binomial regression were used to estimate differences in standardized test scores and incidence ratios of meeting test-based standards, comparing individuals who did and did not receive EI services. RESULTS: The study population consisted of 214 370 children with records through third grade. Of the 13 022 children who had received EI services (6.1%) before 3 years of age, 8516 (65.4%) were male (mean [SD] gestational age, 37.5 [3.8] weeks). When examining third grade standardized test scores, higher absolute test scores were observed among children who received EI in ELA (estimate, 0.045; 95% CI, 0.021-0.069) and greater incidence of meeting test-based standards in both math (incidence ratio, 1.08; 95% CI, 1.06-1.10) and ELA (incidence ratio, 1.09; 95% CI, 1.07-1.12) when comparing propensity score-matched samples. Evidence of heterogeneity was observed, as individuals who required special education, those from households with lower socioeconomic status, and those born to immigrant mothers had greater test score benefits associated with EI. CONCLUSIONS AND RELEVANCE: The findings of this cohort study suggest that EI services for children younger than 3 years with moderate to severe developmental delays or disabilities had tangible academic benefits later in childhood. Future research should investigate the implementation of EI services among individuals with different diagnoses and developmental delays to determine the most beneficial service plans for children with differing needs.