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

ABSTRACT 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.