Sleep duration amongst Icelandic school children

Abstract

Sleep health is important for general well-being and should be prioritized in connection with proper nutrition and regular physical activity for overall quality of life for all ages. In recent decades, studies on adequate nightly sleep duration have found that sleep is important for health, cognitive function and development of young people. Despite increasing amount of sleep studies in recent years, much is still unknown about the prevalence of sleep and sleep habits among young people. Socioeconomic status, family structure, and residential area of the family are among factors that could provide an understanding of different sleep patterns of school children. The aim of the study was to investigate whether sleep duration in Icelandic school children is in accordance with international sleep recommendations, examine the average sleep duration of the students, and assess differences in recommended sleep and sleep duration between different social groups.

The study is based on the national survey of „Health Behavior in School-aged Children“ (HBSC) and was conducted among students in 6th, 8th and 10th grade in 2018. The survey is an international research collaboration which collects data every four years on health and well-being, health-related behavior and social environment of schoolchildren in Europe and North America. Country specific questions are added to the HBSC standardized questionnaire and detailed sleep questions for Icelandic schoolchildren were included in the questionnaire in 2018. A total of 7,159 students participated in the Icelandic HBSC survey in 2018. Among other things, students were asked about their usual bedtime and wake-up times. Criteria for adequate sleep duration were based on international recommendations for young people which are 9–11 hours per night in 6th grade, and 8–10 hours per night for students in 8th and 10th grade.

Overall, about 30% of the children did not meet the recommended sleep duration criteria on weekdays. Boys slept fewer hours than girls, and fewer boys reached the recommended sleep duration. 10th graders slept fewer hours than students in the lower grades and were less likely to get recommended hours of sleep. Students with parents of foreign origin slept fewer hours and achieved recommended sleep less often than other students. Students who lived with both biological parents slept longer and received recommended sleep more often than students in other family types. Students living in urban areas slept longer and achieved recommended sleep more often than students living in rural areas. Some differences in sleeping patterns were also observed by family economic status. The students’ sleep duration on school days had a much higher correlation to their reported bedtimes (r= -0.90; p

A significant proportion of Icelandic schoolchildren did not receive the recommended hours of sleep during the night. It is important to pay closer attention to the overnight sleep of Icelandic school children, especially in those groups where bedtime and sleep duration is most problematic. Sleep characteristics, such as timing of the sleep period and sleep quality are also important factors in sleep hygiene. Behavioral factors known to foster sleep health include regular physical activity and limited screen time. Prioritizing sleep health of school children should be based on cooperation between the school, sports clubs, parents, and public health professionals.