Prevalence, patterns and socio-demographic correlates of sleep duration in adolescents: results from the LabMed study

Objective: The aim of this study was to report the prevalence of adequate sleep and the correlates of sleep duration in Portuguese adolescents aged 12-18 years. Methods: Cross-sectional analysis with 1017 adolescents (471 girls) aged 14.6 +/- 1.8 years. Adolescents self-reported their sleep duration. Results: The percentage of adolescents meeting the guidelines was 72.7%, 60.7% and 51.3%, during a whole week, on weekdays and on weekends, respectively. Boys were always more compliant with the guidelines than girls, for all week categories. A significant difference was found on sleep duration on weekends, between boys and girls (p < 0.001). During weekdays, more adolescents were classified as short sleepers when compared to long sleepers. Younger adolescents were more likely to meet the guidelines over the whole week and on weekdays (OR = 2.23, OR = 2.13, respectively; p < 0.05) and being long sleepers on weekends (OR = 1.49, p < 0.05). Those of medium and low SES were less likely to meet the sleep guidelines for all week categories (p (trend)<0.001). Girls were more likely than boys to meet the guidelines or being long sleepers on weekends (OR = 1.78, OR = 2.85, respectively; p < 0.05). Conclusions: During weekends, the percentage of girls sleeping more than recommended is high, indicating a clear compensation of low sleep duration during weekdays. Those of low SES and older adolescents were less likely to meet the sleep guidelines. Policy makers and researchers should consider the potential effects that SES, gender and age might have on sleep duration, when designing targeted interventions to promote adequate sleep duration. (C) 2021 Elsevier B.V. All rights reserved.