Impact of delaying school start time on adolescent sleep, mood, and behavior

Abstract

Objective: To examine the impact of a 30-minute delay in school start time on adolescents' sleep, mood, and behavior. Design: Participants completed the online retrospective Sleep Habits Survey before and after a change in school start time. Setting: An independent high school in Rhode Island. Participants: Students (n=201) in grades 9 through 12. Intervention: Institution of a delay in school start time from 8 to 8:30 AM. Main Outcome Measures: Sleep patterns and behavior, daytime sleepiness, mood, data from the Health Center, and absences/tardies. Results: After the start time delay, mean school night sleep duration increased by 45 minutes, and average bedtime advanced by 18 minutes (95% confidence interval, 7-29 minutes [t423=3.36; P