Night-time screen-based media device use and adolescents' sleep and health-related quality of life

Objective: The present study investigates the relationship between night-time screen-based media devices (SBMD) use, which refers to use within 1 h before sleep, in both lit and dark rooms, and sleep outcomes and health-related quality of life (HRQoL) among 11 to 12-year-olds. Methods: We analysed baseline data from a large cohort of 6616 adolescents from 39 schools in and around London, United Kingdom, participating in the Study of Cognition Adolescents and Mobile Phone (SCAMP). Adolescents self-reported their use of any SBMD (mobile phone, tablet, laptop, television etc.). Sleep variables were derived from self-reported weekday and/or weekend bedtime, sleep onset latency (SOL) and wake time. Sleep quality was assessed using four standardised dimensions from the Swiss Health Survey. HRQoL was estimated using the KIDSCREEN-10 questionnaire. Results: Over two-thirds (71.5%) of adolescents reported using at least one SBMD at night-time, and about a third (32.2%) reported using mobile phones at night-time in darkness. Night-time mobile phone and television use was associated with higher odds of insufficient sleep duration on weekdays (Odds Ratio, OR=1.82, 95% Confidence Interval, CI [1.59, 2.07] and OR=1.40, 95% CI [1.23, 1.60], respectively). Adolescents who used mobile phones in a room with light were more likely to have insufficient sleep (OR=1.32, 95% CI [1.10, 1.60]) and later sleep midpoint (OR=1.64, 95% CI [1.37, 1.95]) on weekends compared to non-users. The magnitude of these associations was even stronger for those who used mobile phones in darkness for insufficient sleep duration on weekdays (OR=2.13, 95% CI [1.79, 2.54]) and for later sleep midpoint on weekdays (OR=3.88, 95% CI [3.25, 4.62]) compared to non-users. Night-time use of mobile phones was associated with lower HRQoL and use in a dark room was associated with even lower KIDSCREEN-10 score (β=–1.18, 95% CI [–1.85, –0.52]) compared to no use. Conclusions: We found consistent associations between night-time SBMD use and poor sleep outcomes and worse HRQoL in adolescents. The magnitude of these associations was stronger when SBMD use occurred in a dark room versus a lit room.

"This study has shown that night-time use of at least one SBMD, and specifically mobile phones or televisions, was associated with adverse sleep outcomes, particularly insufficient sleep duration, late midpoint of sleep, abnormal catch-up sleep, abnormal social jetlag and poor sleep quality (sleep disturbance) among adolescents. The observed associations were consistent for sleep outcomes on weekdays and weekends. Although night-time use of mobile phones or televisions in a room with the light on was associated with insufficient sleep duration and late midpoint of sleep, the magnitude of the association was higher when night-time use of mobile phones or televisions occurred in darkness. Night-time use of at least one SBMD was also negatively associated with adolescent HRQoL and this association persisted even after excluding adolescents who report any disability. Night-time users of mobile phones in darkness reported worse HRQoL compared to those who did not use mobile phones during night-time." (Mireku et al., 2019: 80).