The child opportunity index and developmental outcomes in early childhood.

Introduction: Neighborhood-level opportunity plays a critical but underexplored role in shaping a child's early developmental outcomes. We hypothesized that higher neighborhood opportunities would be associated with higher developmental outcomes in early childhood. Methods: This observational cohort study included children from Northern Virginia, born between 2020 to 2023. At age 2-3 years, children completed the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Zip-code level neighborhood opportunity scores were derived from the Child Opportunity Index (COI). Associations between COI scores and BSID-III cognitive, language and motor outcomes were examined, with consideration of maternal education and child ethnicity. Results: COI scores were positively associated with BSID-III cognitive and language outcomes, showing a consistent gradient across geographical levels. The social/economic subdomain showed the strongest associations. No associations were observed in motor outcomes. Maternal education explained slightly more variance in developmental outcomes than the COI, though the difference was not significant. Hispanic/Latino children scored lower than non-Hispanic/Latino peers across all geographical levels, with the largest disparities in low health/environment neighborhoods. Lower neighborhood opportunity is associated with poorer developmental outcomes; with disparities most pronounced among Hispanic/Latino children. Discussion: These findings underscore the need for focused interventions addressing neighborhood and family-level resources to better support early child development.