Background and aims To determine the association between screen time and child outcomes.

Methods 706 mothers who were part of a longitudinal pregnancy cohort were mailed a questionnaire when children were 6 to 8 years of age. Mothers reported the amount of time children spent with computers, television, and video games on an average school day (screen time), BMI, child behavior, and physical activity. Using Pearson chi-square tests or independent sample t-tests, children who had more than 2 hours screen time on an average school day were compared to those who had 2 hours or less.

Results 450 mothers completed the questionnaire (response rate 64%). 30% of children had more than 2 hours of screen time during school days, and these children were more likely to take longer than 30 minutes to fall asleep (25% vs. 15%, p=0.006) and less likely to exhibit prosocial behavior (mean 12.88 vs. 13.71, p=0.028). There was no association between screen time and BMI or time spent in physical activity. Compared to mothers of children had 2 hours or less of screen time, mothers of children who had more than 2 hours of screen time were less likely to be satisfied with their child’s level of physical activity (76% vs. 89%, p<0.001).

Conclusions The Canadian Paediatric Society guideline recommends no more than 2 hours of screen time per day. More than a third of children exceed this limit on school days, and this may have important implications for children’s sleep and behavior in childhood.