A Longitudinal Analysis of National Data

Results: Before age 3 years, the children in this study watched an average of 2.2 hours per day; at ages 3 to 5 years, the daily average was 3.3 hours. Adjusted for the covariates mentioned earlier, each hour of average daily television viewing before age 3 years was associated with deleterious effects on the Peabody Individual Achievement Test Reading Recognition Scale of 0.31 points (95% confidence interval [CI], −0.61 to −0.01 points), on the Peabody Individual Achievement Test Reading Comprehension Scale of 0.58 points (95% CI, −0.94 to −0.21 points), and on the Memory for Digit Span assessment from the Wechsler Intelligence Scales for Children of −0.10 points (95% CI, −0.20 to 0 points). For the Reading Recognition Scale score only, a beneficial effect of television at ages 3 to 5 years was identified, with each hour associated with a 0.51-point improvement in the score (95% CI, 0.17 to 0.85 points).