Search

To evaluate the secular trends of sleep-wake patterns of Hong Kong preschool children. Kindergartens from the four geographical regions of Hong Kong were randomly invited to take part in a sleep survey in 2012 and again in 2018. The parent-completed questionnaire provided information on socioeconomic status (SES), children's, and parental sleep-wake patterns. Secular trends and risk factors associated with short sleep duration in preschoolers were explored. A sample of 5048 preschool children was included in the secular comparison, with 2306 and 2742 from the 2012 and 2018 surveys, respectively. A higher percentage of children in 2018 (41.1% vs 26.7%, p < 0.001) did not achieve the recommended sleep duration. During the survey years, sleep duration decreased by 13 ([95%CI: 18.5 to −8.1]) and 18 min ([95%CI: 23.6 to −12.2]) on weekdays and weekends, respectively. The overall trend of nap decrease was not significant. Sleep onset latency significantly increased on both weekdays (6 min [95%CI: 3.5 to 8.5]) and weekends (7 min [95%CI: 4.7 to 9.9]). Children's sleep duration was positively correlated with parental sleep duration with a correlation coefficient ranging from 0.16 to 0.27 (p < 0.001). A significant proportion of Hong Kong preschool children did not achieve the recommended amount of sleep. A downward secular trend in sleep duration was observed during the survey period. Public health measures to improve sleep duration in preschool children should be a high priority. • A downward secular trend in sleep duration is observed in Hong Kong preschoolers. • Parental sleep duration is also significantly shorter during the survey period. • Bedtime access to electronic media devices is a risk factor for reduced sleep duration. [ABSTRACT FROM AUTHOR]

To evaluate sleep duration in a representative sample of preschoolers and examine the relationships between screen time and use of different electronic media devices with sleep duration and social jetlag. 2903 preschoolers were included. Parent-completed questionnaire provided information on socioeconomic status, electronic media use of the children and sleep patterns of both parents and children. Preschoolers were divided according to whether they met the international screen time recommendations for their age. Comparisons between the two groups in various sleep measures and effects of different devices on sleep were evaluated. 40% of preschoolers in our cohort did not achieve the recommended sleep duration. Subjects who adhered to the screen time recommendations were from families of higher socioeconomic status, had longer sleep duration and better sleep habits. Each hour increase on portable electronic device use was associated with 11 (95%CI: −15 to −6) and 6 (95%CI: −10 to −2) minutes less of average daily sleep duration in boys and girls, respectively. Every additional hour of non-portable electronic devices use was associated with 3 min shift in social jetlag in boys. Presence of electronic devices in bedroom and their use at bedtime increased risk of social jetlag in boys with an OR of 1.40 (95%CI: 1.01 to 1.92) and 1.39 (95%CI: 1.00 to 1.95) respectively. A significant proportion of preschoolers does not obtain the recommended amount of sleep. Screen time in preschoolers affects not only sleep duration but also leads to circadian discrepancy. • Representative description of Hong Kong preschoolers' sleep reveals that sleep deprivation is common among this population. • Nearly three quarters of preschoolers in Hong Kong have more than one hour of screen time per day. • Screen time in preschoolers may be detrimental not only for sleep duration but also circadian discrepancy. • Portable electronic device use has a stronger independent association with sleep duration than non-portable electronic device use in boys. [ABSTRACT FROM AUTHOR]