Relationship between screen time and sleep among Finnish preschool children: results from the DAGIS study.

STUDY OBJECTIVES:To examine the associations between screen time, the time spent on different screen devices, and sleep in a sample of Finnish preschool children. METHODS:The current study analyzed cross-sectional data from the DAGIS study carried out in Finland in 2015-2016 on 736 children aged 3-6 years. Parents reported in a 7-day diary the durations the child used screen devices daily, with separate details about watching TV or DVDs, using tablets or smartphones, and using computers. In addition, parents reported children's bedtimes and wake-up times, which were further used in calculating sleep duration. Parents answered questions regarding their child's sleep consistency. Statistical analyses included adjusted general linear modeling. RESULTS:An hourly increase in total screen time was associated with 11 min later bedtime (p < 0.001) and 10 min shorter sleep duration (p < 0.001). More TV/DVD watching was associated with later bedtimes (p = 0.016) and a shorter sleep duration (p = 0.001). More smartphone/tablet use was associated with later bedtimes (p = 0.005), later wake-up times (p = 0.038), and weaker sleep consistency (p = 0.024). More computer use was associated with later bedtimes (p = 0.046). Results did not differ between genders. CONCLUSIONS:Increased screen time was associated with later bedtimes and shorter sleep duration among preschool children. Adverse associations with sleep outcomes were found for each screen device. Attention should be paid to promoting balanced use of screens and regular sleep habits in young children.