Secular trends in sleep and circadian problems among adolescents in Hong Kong: From 2011-2012 to 2017-2019

The study aimed to investigate secular trends in sleep and circadian problems in Hong Kong Chinese adolescents. This study analyzed cross-sectional data from two large-scale school-based sleep surveys conducted in 2011-2012 and 2017-2019. Sleep and circadian problems, including sleep-wake pattern, insomnia, chronotype, social jetlag, daytime sleepiness, and other sleep-related factors, were compared between two survey years. A total of 8082 adolescents (5639 students in 2011-2012 [Mean age: 14.4 years, 50.9% boys] and 2443 students in 2017-2019 [Mean age: 14.7 years, 54.0% boys]) were included in this 7-year study. The average time in bed of Hong Kong adolescents decreased from 8.38 hours to 8.08 hours from 2011-2012 to 2017-2019. There was a 0.28-hour delay in weekday bedtime, 0.54-hour advance in weekend wake-up time, and a 0.36-hour decline in average time in bed, resulting in increased trends of sleep loss (Time in bed