RESUMEN
Prolonged viewing of screen-based media is associated with poor sleep in children. Previous systematic reviews have analysed the effectiveness of interventions that aim to limit children's screen use; however, none have evaluated its effect on sleep. The aim of this systematic review was to evaluate the effect of interventions that incorporate strategies to control children's screen use on screen use and sleep. The databases Pubmed, Embase, Eric, Scopus and PsycInfo were searched during October 2017 and updated in February 2019 for experimental studies with a control that assessed interventions to control screen use in children aged 2-14 years and reported both screen use and sleep outcomes. From 3,872 initial records, 11 studies (six randomized control [RCT], four cluster RCT and one cluster, quasi-experimental) were eligible for inclusion. A total of 4,656 children aged 2-13 years were included in the studies. The mean reduction in screen time was 0.56 hr (33 min)/day (95% confidence interval [CI], 0.92, 0.20) and the mean sleep duration increased by 0.19 hr (11 min)/day (95% CI, 0.05, 0.33). Bedtime was advanced by 0.16 hr (10 min) on weekdays and by 1.0 hr at the weekend. Subgroup analyses indicated stronger intervention effects for interventions of shorter duration (<3 months), which specifically targeted screen use or sleep, and those with direct participant contact. In conclusion, small improvements in screen time and sleep duration can be achieved in children. It is not possible to determine if a reduction in screen time directly improves sleep, due to the limited number of studies, the presence of co-interventions, issues with studies' methodological quality and heterogeneity.