O2038: Subjective vs Objective Measures of Sleep in Adolescents: A Multi-Year Longitudinal Study

Background: The National Sleep Foundation (NSF) recommends 9-11 hours of sleep/night for adolescents (ages 6-13) and 8-10 hours/night for teenagers (ages 14-18). Increases in factors such as academic, athletic, and extracurricular demands during middle and high school hinder 14% to 68% of adolescents from meeting these recommendations. Current longitudinal studies on adolescent sleep duration trends take measurements at 2-5 year intervals. The purpose of this study is to further elucidate adolescent sleep duration trends by collecting both ActiGraph and self-reported sleep data annually from middle though high school.

Methods: Students from a private academic institution were followed longitudinally from 7th to 12th grade. Sleep data was obtained from ActiGraph accelerometer watches during 2-week spans each year. Students also self-reported sleep via diaries during periods of watch wear. The Sadeh algorithm was utilized to analyze sleep and movement activity with a pediatric pulmonology and sleep medicine physician. Mixed-models were used to analyze sleep data trends over time. Pearson’s Correlation and Bland-Altman analysis were used to examine the relationship between ActiGraph and self-reported sleep hours.

Results: 107 participants were followed across 6 years. Average sleep hours were calculated per participant per 2-week data collection span. 159 ActiGraph average sleep hours and 284 self-reported average sleep hours entries were collected. The self-reported data showed a negative trend in average sleep hours with grade, decreasing from 8.5 hours in 7th grade to 7.3 hours in 12th grade (Figure 1, Table 1). Significant differences were found for 7th grade vs. all other grades (p < 0.001) and for 8th grade vs. 11th and 12th grade (p < 0.03). Similar trends were observed for ActiGraph average sleep hours with all grades except for 10th being significantly different from the 7th grade (p < 0.03). There was a significant correlation between the self-reported and ActiGraph average sleep hours (Pearson’s rho=0.42, p< 0.001). However, self-reported sleep time was on average 1.4 (95% CI: [1.2, 1.6]) hours greater than ActiGraph measured sleep time with limits of agreement of -0.6 to 3.4.

Conclusion: Adolescents are having a significant reduction in sleep duration after 7th grade. Although there is a strong correlation between the ActiGraph and self-reported data, students tend to overestimate how much sleep they are getting by more than 1 hour. This study shows that adolescents are not getting their recommended sleep hours, particularly during high school. This sleep deficit may be more than previous ActiGraph studies have suggested with our ActiGraph data reporting a decrease in average sleep hours from 6.77 hours in 7th grade to 6.01 hours in 12th grade, compared to the results of other ActiGraph studies which suggest a range of 6.85-8.1 hours for ages 13-15 and a decrease from 7.43 hours in 10th grade to 7.27 hours in 12th grade.