Screen media use by Portuguese children in 2009 and 2016: a repeated cross-sectional study

Background: Few studies have examined how access to mobile media is disrupting more traditional forms of media use.
Aim: Examine screen-time in 2009/10 and 2016/17 among children aged 3 to 6 years and assess potential socio-economic determinants of adherence to screen-time recommendations.
Method: Two independent cross-sectional studies included 6874 Portuguese children. Screen-time (including television, computer, tablet and smartphone) and proxy measures to calculate socioeconomic position (SEP) were parent-reported using a standardized questionnaire. Screen-time and adherence to screen-time recommendation were calculated for both periods. Determinants of excessive screen-time were identified using adjusted logistic regression models.
Results: In 2009/10 screen-time averaged 107min/day for preschool children and 149min/day for school-aged children. In 2016/17 values were 142min/day and 173min/day, respectively. Screen-time allocated to television was the highest, independently of children’s age. In 2016/17, mobile media use was common among preschool (37min/day) and school-aged children (43min/day). Exceeding the recommended screen-time was more prevalent in boys than girls (adjusted odds ratio [aOR] between 1.02-1.59) and in children whose parents had lower education levels or were unemployed (aOR between 1.00-2.23).
Conclusion: Screen-time was high among preschool children, emphasizing the need for earlier interventions, particularly among those from lower-SEP who had higher risk of exceeding the screen-time recommendations.