The Impact of Sleep Loss on Screen Time in Children: Secondary Analyses of a Randomised Crossover Trial Using Objective Measures of Screen Time.

Background: How reduced sleep impacts screen time in children is unclear.

Objectives: To explore how reduced sleep impacts objectively measured screen use.

Methods: One hundred and five children (8-12 years) with caregiver-reported sleep of 8-11 h/night were randomised to 7 nights sleep extension (go to bed 1 h earlier) or sleep restriction (bed 1 h later) in a crossover trial with a 7-night washout between conditions. Sleep and time awake were measured using waist-worn accelerometry (ActiGraph wGT3X-BT) and screen time using wearable cameras (Brinno TLC130 Timelapse) and questionnaires. Camera images were coded as time spent on screens (raw data), including imputation for blocked images (Rules 1 and 2). Within-person differences (95% CI) were calculated in those with matched camera data across sleep intervention weeks, in minutes and as percentage of awake time.

Results: Screen time before school or on weekends did not differ in the 49 children (10.4 years, 51% female, 41% overweight, 78% European) with suitable camera data. After school, children appeared to have similar screen time using raw data (median difference; 25th, 75th percentiles: 18.7 min; -10.2, 72.5), but greater screen time during sleep restriction compared with extension after allowance for blocked images (Rule 2: 66.3 min; 7.5, 102.9 or 6% of awake time; 0.5, 10.0). Parents (n = 98) reported greater total screen use in children during the sleep restriction week (mean difference; 95% CI: 16.8 min; 1.8, 31.8).

Conclusions: In this secondary analysis, getting less sleep appeared to increase screen time in children during the weekday afternoon and evening hours, compared to when they received more sleep.

Trial Registration: ACTRN12618001671257 Australian New Zealand Clinical Trials Registry; ANZCTR.