Limits to screen use associated with increased non-sedentary behavior in children

1. In this clustered, randomized controlled trial, children who were limited to 3 hours of screen time per week spent an additional 45 minutes of non-sedentary time per day compared to the control group.

2. At baseline, children had an average of 36 hours of screen media use per week.

Evidence Rating Level: 1 (Excellent)

Study Rundown: High rates of screen media time among children have raised concerns regarding poorer health outcomes, such as decreased physical activity and impaired sleeping habits. Current research is limited by poor compliance to screen reduction interventions. This clustered randomized controlled trial examined the association between reducing screen media use and subsequent impact on physical activity and sleep in children. Approximately 180 children and 165 adults from 89 families in Denmark were included in the analysis, and randomized to the intervention (limit of 3 hours of screen use per week) or control (no changes to screen use). Participants were monitored with accelerometers over 2 weeks for non-sedentary behavior (i.e., all waking activities other than sitting and lying down), in addition to electroencephalography to monitor sleep parameters at baseline and at days 12-14. Overall, children in the intervention group spent an additional 45 minutes per day engaging in non-sedentary behavior, compared to the control group (p<0.001). There were no significant differences across sleep outcomes and no changes in parental behavior or sleep outcomes. Because the study could not be blinded, the intervention group may have been motivated to increase non-sedentary behavior during the study period. This study provides data that suggests non-sedentary behavior in children can be increased with interventions that reduce screen time. Future research should investigate the feasibility of programs designed to decrease screen time over a significant time period.

Click to read the study in JAMA Pediatrics

Relevant Reading: The effect of interventions targeting screen time reduction: a systematic review and meta-analysis  

In-Depth [randomized controlled trial]: Between 2019-2021, a total of 89 families (181 children and 164 parents) were enrolled in Denmark via an electronic survey. At least one parent had to use >2.4 hours of screen media use per day, and have at least one child at home aged 6-10 years. 86 children from 45 families were randomized to the screen media reduction intervention (i.e., a maximum of 3 hours of screen use per week) and 95 children from 44 families were allocated to the control group (i.e., no change to screen media use). Families were followed up after 2 weeks and were tracked for screen use via tracking devices during that time. Smartphones were removed from the household for at least one adult and all children in the home, with non-smart phones provided with call and text functions. Non-sedentary behavior was measured using an accelerometer worn by participants. Compliance in the intervention group was considered as <7 hours per week of screen time, and overall, there was high compliance (97%). Sleep measures (i.e., sleep duration, onset latency, wake after sleep onset) was assessed using electroencephalography at baseline and at days 12-14 of the study, as well as through sleep diaries. Overall, the intervention group showed 45 additional minutes of non-sedentary behavior (95% CI 29-64 minutes per day, p<0.001), corresponding to a 30% mean difference in non-sedentary activity during leisure. There was no impact on parameters of sleep. Furthermore, there were no significant changes in non-sedentary behavior or sleep in adults.

Image: PD

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