Disparities in the prevalence of cognitive delay: how early do they appear?
Cognitively delayed children are at risk for poor mental and physical health throughout their lives. The economically disadvantaged and some race/ethnic groups are more likely to experience cognitive delay, but the age at which delays first emerge and the underlying mechanisms responsible for disparities are not well understood. The objective of this study was to determine when sociodemographic disparities in cognitive functioning emerge, and identify predictors of low cognitive functioning in early childhood. Data were from 7308 singleton and 1463 multiple births in the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), a nationally representative cohort of children born in the USA in 2001. Multiple logistic regression analyses examined associations between sociodemographic characteristics and low cognitive functioning at 9 and 24 months, and tested whether gestational and birth-related factors mediate these associations. Sociodemographic characteristics were statistically sign
