123: A Comparison of Actigraphic and Self-Reported Sleep Timing in Adolescents

Adolescent sleep deprivation is common and has a significant negative impact on health and well-being. Pediatric health care professionals must measure sleep timing accurately in order to identify and then treat sleep deprivation in this age group. Currently, parents often respond on behalf of their child and are inaccurate in reporting their child's sleep timing. It is possible that asking the adolescent directly about their sleep patterns may yield more accurate sleep information. However, there is a lack of research evaluating how well adolescents are able to estimate their sleep timing. The current study seeks to compare adolescent self-reported and objective actigraphy estimates of bedtime and wake time in order to assess how valid adolescents are in reporting their sleep timing on the weekdays and weekends. Adolescents were recruited from a high school in Montreal and survey completion took place in classrooms during school hours. Thirty-five participants answered a four-item questionnaire pertaining to when they typically went to bed and woke up on weekdays and weekends. Sleep duration was then calculated as a function of bedtime and wake time. All participants underwent actigraphy and completed sleep logs for five consecutive weekdays. Twenty-seven of the 35 participants also underwent actigraphy and completed sleep logs on the weekend. There were significant positive correlations between actigraphy and survey data for sleep variables including weekday sleep start time (r=0.71), end time (r=0.77) and sleep duration (r=0.63), and weekend sleep start time (r=0.68) and end time (r=0.82) but not sleep duration (r=0.22). While adolescents reported sleeping for an average of 10 h on weekend nights, actiwatch data indicated that they were sleeping for only 8.8 h. Adolescents can accurately report their sleep timing on weekdays. One explanation for the non-significant correlation between actigraphy and survey weekend sleep duration data is that actigraphy sometimes interprets movement during sleep as a state of wake, thus causing a decrease in the estimation of actual sleep. In addition to asking parents about their child's sleep habits and assessing sleep objectively, health care professionals should consider asking adolescents directly about their sleep timing.