Significant differences in sleep conditions of adolescents in various countries

Sleep-related problems in adolescents are a global headache. Research regarding this issue use different methods and cover people of different age groups from different countries. Currently, direct transnational comparative research among different countries lack sufficient statistics. At present, Health Behavior in School-aged Children (HBSC) is one of the biggest quantitative research centers, whose data on adolescent sleep involve 24 countries and regions in Europe and North America.

This research indicates, of the 165,793 adolescents from 24 countries and regions, lack of sleep during school days is a common problem in all countries. Around 25% of adolescents will have at least one day each week with difficulty falling asleep. Adolescents who reach the suggested sleep time during school days (9-11 hours for children between 5-13 years old, 8-10 hours for adolescents between 14-17 years old) are between 32% (Poland) and 86% (the Flemish Region in Belgium), and between 79% (Greece) and 92% (the Flemish Region in Belgium) during non-school days.

Sleep times for adolescents among different countries vary significantly. Adolescents in the Flemish Region in Belgium have the longest average sleep time, and the earliest bedtime (21:42 during school days, 23:14 during non-school days). Adolescents in Poland (7 hours and 47 minutes) and Greece (9 hours and 31 minutes) have the shortest and longest average sleep durations during school days and non-school days. Adolescents in Greece (23:18) and Spain (0:54) have the latest average bedtimes during school days and non-school days. In 15 countries, boys on average sleep longer than girls during school days (the difference is small, of less than 10 minutes). During non-school days, in every country surveyed, on average, girls sleep longer than boys. The average time for boys going to sleep is usually later, 2-10 minutes later than girls during school days, and 1-27 minutes later than girls during non-school days. Compared with gender difference, the difference in adolescents’ sleep pattern is more correlated with age. Older adolescents sleep less and go to bed later during school days.

It is worth noting that in the countries surveyed, adolescents from the Flemish Region in Belgium perform best in sleep duration and bedtime. Adolescents from Greece sleep the shortest during non-school days, and go to sleep the latest during school days. Adolescents from Poland sleep the shortest during school days and achieve the lowest percentage of suggested sleep duration. School days or not, adolescents from Hungary on average wake up the earliest, whereas adolescents from Spain on average wake up the latest. For adolescents from Moldova and Scotland, sleep condition is highly related to socioeconomic status. These conclusions signify that factors on a national level have greater influence adolescents’ sleep conditions.

However, this study did not look at other factors that affect sleep. There are other studies on other factors related to students’ sleep. In 2016, Senior Lecturer Woods and other scholars from Glasgow University in England found the use of social media, especially nighttime social media activities and the emotional engagement on social media affects sleep quality. In 2018, a study by demography professor Bilali and others from Bocconi University in Italy shows that playing computer games is strongly correlated with sleep deprivation. Playing an extra 30 minutes of computer games would increase the possibility of sleep deprivation by 50%. In 2017, Severson and other researchers from the Bergen Public Health Research Institute in Norway found that Norwegian adolescents who experienced a descend in social hierarchy are more likely to have dyscoimesis. Assistant professor Voulgaris and others from the School of Civil and Environmental Engineering at California Polytechnic State University in the U.S. found in a research that commuting time has correlation with sleep time: every extra minute of commuting time would reduce sleep time by 1.3 minutes. The choice of commuting transportation also affects sleep. Other studies have shown that health cultures (such as exercise and diet), geographical locations, and seasons are all factors that impact sleep.

Author: Zhang Liwei, Editor-in-Chief of “World Education Information” at the Education Management Information Center, Ministry of Education