Objective: To determine whether duration and content of media exposure in 6-month-old infants are associated with development at age 14 months.
Design: Longitudinal analysis of 259 mother-infant dyads participating in a long-term study related to early child development, from November 23, 2005, through January 14, 2008.
Setting: An urban public hospital.
Participants: Mothers with low socioeconomic status and their infants.
Main exposure: Duration and content of media exposure at age 6 months.
Main outcome measures: Cognitive and language development at age 14 months.
Results: Of 259 infants, 249 (96.1%) were exposed to media at age 6 months, with mean (SD) total exposure of 152.7 (124.5) min/d. In unadjusted and adjusted analyses, duration of media exposure at age 6 months was associated with lower cognitive development at age 14 months (unadjusted: r = -0.17, P < .01; adjusted: β = -0.15, P = .02) and lower language development (r = -0.16, P < .01; β = -0.16, P < .01). Of 3 types of content assessed, only 1 (older child/adult-oriented) was associated with lower cognitive and language development at age 14 months. No significant associations were seen with exposure to young child-oriented educational or noneducational content.
Conclusions: This study is the first, to our knowledge, to have longitudinally assessed associations between media exposure in infancy and subsequent developmental outcomes in children from families with low socioeconomic status in the United States. Findings provide strong evidence in support of the American Academy of Pediatrics recommendations of no media exposure prior to age 2 years, although further research is needed.