Time trends and predictors of difficulties in getting to sleep among adolescents from six Nordic countries 2002-2018

Aims: Sleep difficulties among adolescents are of a significant concern given its associations with adverse health outcomes. The aims of the present study were to examine trends and predictors of self-perceived difficulties in getting to sleep among adolescents in the Nordic countries.Methods: The study was based on cross-sectional data from 10- to 17- year-olds (N = 139,799) from six Nordic countries (Sweden, Iceland, Norway, Denmark, Greenland, and Finland) participating in the international Health Behaviour in School-aged Children (HBSC) study, collected via six survey rounds in the period 2002-2018.Results: Since 2002, the prevalence of self-perceived difficulties in getting to sleep has risen in all Nordic countries. However, from 2014 to 2018, the trend of adolescents reporting difficulty more than weekly increased in Denmark, Finland, Greenland, and Norway, whereas it was mostly stable in Sweden, and Iceland showed a reduction. Predictors of difficulties in getting to sleep varied across countries, but younger age, reduced life satisfaction, decreased physical activity, feeling low, and feeling nervous were common predictors across the six countries. Gender and perceived family wealth had different effects on difficulties getting to sleep in different countries.Conclusions: Prevalence of and trends in difficulties getting to sleep varied by country, with a concerning rise identified in Greenland, 2006-2018. Predictors such as feeling low, feeling nervous, age, gender, life satisfaction, physical activity, and perceived family wealth varied by country and thus emphasize the need for tailored interventions to address diverse challenges in adolescent sleep health.