O002 Sleepy teens and the use of screens: A repeated measures analysis examining the relationship between pre-bedtime screen use and sleep

Abstract Aims Pre-bedtime screen use among adolescents is highly prevalent and fast-paced, often involving multiple devices, and frequent switching between activities, which is presumed to be harmful to sleep. The aim of this study was to determine how objectively-measured evening screen time influenced sleep in young adolescents. Methods BED was a repeated-measures observational study in 85 healthy adolescents (11-14.9 years). Objective screen time data were captured over four non-consecutive nights using video cameras from two hours before bedtime until the adolescent attempted sleep (shuteye time) and coded using a reliable protocol (κ ≥ 0.8). Sleep outcomes (sleep timing, total sleep time, and WASO) were measured objectively via wrist-worn AX3 accelerometers. Screen use was related to sleep on a night-by-night basis using a mixed-effects regression model, which considered participant as a random effect and adjusted for weekends. Results Screen time in the two hours before bed had little effect on sleep that night. However, once in bed, screen time delayed sleep onset by 35 (95% CI: 20, 50) minutes compared to nights without screen use. Interactive screen use reduced TST more than passive screen use (9 compared with 4 minutes for every 10 minutes of use, but time since last screen use did not impact any measure of sleep health examined. Conclusion Improved methodology shows that screen time may impair sleep once in bed, especially if interactive. Current sleep hygiene recommendations to restrict all screen time before bed seem neither achievable nor appropriate within this age group.