Children using devices such as smartphones and tablets at bedtime have over double the risk of a disrupted night’s sleep compared to children without access to such devices, according to a study led by researchers from King’s College London.
Previous research suggests that 72% of children and 89% of adolescents have at least one device in their bedrooms and most are used near bedtime. The speed at which these devices have developed – and their growing popularity among families – has outpaced research in this area, meaning that the impact on sleep is not well understood.
This new research is a review of 20 existing studies from four continents, involving more than 125,000 children aged 6-19 (with an average age of 15). The researchers from King’s found that bedtime use of media devices was associated with an increased likelihood of inadequate sleep quantity, poor sleep quality, and excessive daytime sleepiness. Bedtime use was classified as engagement with a device within 90 minutes of going to sleep.
They also found that the presence of a media device in the bedroom, even without use, was associated with an increased likelihood of poor sleep. One potential reason for this is that the ‘always on’ nature of social media and instant messaging means children are continuously engaged with devices in their environment, even when they are not actively using them.
It is thought that screen-based media devices adversely affect sleep through a variety of ways, including delaying or interrupting sleep time; psychologically stimulating the brain; and affecting sleep cycles, physiology and alertness.
Sleep disturbance in childhood is known to have adverse effects on health, including poor diet, obesity, sedative behaviour, reduced immune function and stunted growth, as well as links with mental health issues.
Dr Ben Carter from King’s College London, said: ‘Our study provides further proof of the detrimental effect of media devices on both sleep duration and quality. “Sleep is an often undervalued but important part of children’s development, with a regular lack of sleep causing a variety of health problems. With the ever-growing popularity of portable media devices and their use in schools as a replacement for textbooks, the problem of poor sleep amongst children is likely to get worse. Our findings suggest that an integrated approach involving parents, teachers, and healthcare professionals is necessary to reduce access to these devices and encourage good sleeping habits near bedtime.”
Importance: Sleep is vital to children’s biopsychosocial development. Inadequate sleep quantity and quality is a public health concern with an array of detrimental health outcomes. Portable mobile and media devices have become a ubiquitous part of children’s lives and may affect their sleep duration and quality.
Objective: To conduct a systematic review and meta-analysis to examine whether there is an association between portable screen-based media device (eg, cell phones and tablet devices) access or use in the sleep environment and sleep outcomes.
Data Sources: A search strategy consisting of gray literature and 24 Medical Subject Headings was developed in Ovid MEDLINE and adapted for other databases between January 1, 2011, and June 15, 2015. Searches of the published literature were conducted across 12 databases. No language restriction was applied.
Study Selection: The analysis included randomized clinical trials, cohort studies, and cross-sectional study designs. Inclusion criteria were studies of school-age children between 6 and 19 years. Exclusion criteria were studies of stationary exposures, such as televisions or desktop or personal computers, or studies investigating electromagnetic radiation.
Data Extraction and Synthesis: Of 467 studies identified, 20 cross-sectional studies were assessed for methodological quality. Two reviewers independently extracted data.
Main Outcomes and Measures: The primary outcomes were inadequate sleep quantity, poor sleep quality, and excessive daytime sleepiness, studied according to an a priori protocol.
Results: Twenty studies were included, and their quality was assessed. The studies involved 125 198 children (mean [SD] age, 14.5 [2.2] years; 50.1% male). There was a strong and consistent association between bedtime media device use and inadequate sleep quantity (odds ratio [OR], 2.17; 95% CI, 1.42-3.32) (P < .001, I2 = 90%), poor sleep quality (OR, 1.46; 95% CI, 1.14-1.88) (P = .003, I2 = 76%), and excessive daytime sleepiness (OR, 2.72; 95% CI, 1.32-5.61) (P = .007, I2 = 50%). In addition, children who had access to (but did not use) media devices at night were more likely to have inadequate sleep quantity (OR, 1.79; 95% CI, 1.39-2.31) (P < .001, I2 = 64%), poor sleep quality (OR, 1.53; 95% CI, 1.11-2.10) (P = .009, I2 = 74%), and excessive daytime sleepiness (OR, 2.27; 95% CI, 1.54-3.35) (P < .001, I2 = 24%).
Conclusions and Relevance: To date, this study is the first systematic review and meta-analysis of the association of access to and the use of media devices with sleep outcomes. Bedtime access to and use of a media device were significantly associated with the following: inadequate sleep quantity, poor sleep quality, and excessive daytime sleepiness. An integrated approach among teachers, health care professionals, and parents is required to minimize device access at bedtime, and future research is needed to evaluate the influence of the devices on sleep hygiene and outcomes.
Ben Carter, Philippa Rees, Lauren Hale, Darsharna Bhattacharjee, Mandar S Paradkar