Screen use, physical activity, and sleep among adolescents: A latent class analysis of 4,421 Danish adolescents’ movement patterns and the correlation with mental health

Background and aims: Screen use, physical activity, and sleep independently impact adolescents’ mental health, yet further exploration is needed to understand its dynamic impact. This study aimed to examine how movement behaviour cluster in Danish adolescents and how these movement patterns correlate with mental health. Methods: Data were collected among Danish adolescents as part of the cross-sectional Health Behaviour in School-Aged Children (HBSC) study in 2018 and 2022. Study population comprised 4421 adolescents (51.5 % girls, age 11, 13 and 15). Latent class analysis was performed separately for boys and girls based on self-reported screen time (5 items), physical activity level (2 items), and sleep duration (1 item). Associations between classes and mental health (mental wellbeing, psychosomatic complaints, and body image) were evaluated using adjusted regression models stratified on sex. Results: Three movement patterns were identified. Class 1 represented medium screen users with high physical activity (34.3 % of boys; 28.1 % of girls); class 2 represented medium screen users with low physical activity (41.8 %; 42.5 %); and class 3 represented high screen users with short sleep duration (23.8 %; 29.3 %). Compared to class 1, adolescents in class 2 and 3 reported substantially poorer mental wellbeing, more psychosomatic complaints, and poorer body image, especially girls in class 3. Conclusion: Screen use, sleep, and physical activity behaviour tend to group in three movement patterns among Danish adolescents. The identified patterns were associated with notable differences in mental health outcomes. Results emphasize the benefits of high physical activity, low screen time and sufficient sleep, supporting interventions targeting multiple movement behaviours at once.