Nicole G Nahmod1, Soomi Lee2, Orfeu M Buxton3, Anne-Marie Chang2, Lauren Hale4. 1. Department of Biobehavioral Health, Pennsylvania State University. Electronic address: NikkiN@psu.edu. 2. Department of Biobehavioral Health, Pennsylvania State University. 3. Department of Biobehavioral Health, Pennsylvania State University; Division of Sleep Medicine, Harvard Medical School; Sleep Health Institute, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital; Department of Social and Behavioral Sciences, Harvard Chan School of Public Health. 4. Program in Public Health; Department of Family, Population and Preventive Medicine, Stony Brook University.
Abstract
OBJECTIVES: High school start times are a key contributor to insufficient sleep. This study investigated associations of high school start times with bedtime, wake time, and time in bed among urban teenagers. DESIGN: Daily-diary study nested within the prospective Fragile Families and Child Wellbeing Study. SETTING: Twenty US cities. PARTICIPANTS: Four hundred thirteen teenagers who completed ≥1 daily diary report on a school day. MEASUREMENTS: Participating teens were asked to complete daily diaries for 7 consecutive days. School-day daily diaries (3.8±1.6 entries per person) were used in analyses (N=1555 school days). High school start time, the main predictor, was categorized as 7:00-7:29 am (15%), 7:30-7:59 am (22%), 8:00-8:29 am (35%), and 8:30 am or later (28%). Multilevel modeling examined the associations of school start times with bedtime, wake time, and time in bed. Models adjusted for age, sex, race/ethnicity, household income, caregiver's education, and school type. RESULTS: Teens with the earliest high school start times (7:00-7:29 am) obtained 46 minutes less time in bed on average compared with teens with high school start times at 8:30 am or later (P<.001). Teens exhibited a dose-response relationship between earlier school start times and shorter time in bed, primarily due to earlier wake times (P<.05). Start times after 8:30 am were associated with increased time in bed, extending morning sleep by 27-57 minutes (P<.05) when compared with teens with earlier school start times. CONCLUSION: Later school start times are associated with later wake times in our large, diverse sample. Teens starting school at 8:30 am or later are the only group with an average time in bed permitting 8 hours of sleep, the minimum recommended by expert consensus for health and well-being.
OBJECTIVES: High school start times are a key contributor to insufficient sleep. This study investigated associations of high school start times with bedtime, wake time, and time in bed among urban teenagers. DESIGN: Daily-diary study nested within the prospective Fragile Families and Child Wellbeing Study. SETTING: Twenty US cities. PARTICIPANTS: Four hundred thirteen teenagers who completed ≥1 daily diary report on a school day. MEASUREMENTS: Participating teens were asked to complete daily diaries for 7 consecutive days. School-day daily diaries (3.8±1.6 entries per person) were used in analyses (N=1555 school days). High school start time, the main predictor, was categorized as 7:00-7:29 am (15%), 7:30-7:59 am (22%), 8:00-8:29 am (35%), and 8:30 am or later (28%). Multilevel modeling examined the associations of school start times with bedtime, wake time, and time in bed. Models adjusted for age, sex, race/ethnicity, household income, caregiver's education, and school type. RESULTS: Teens with the earliest high school start times (7:00-7:29 am) obtained 46 minutes less time in bed on average compared with teens with high school start times at 8:30 am or later (P<.001). Teens exhibited a dose-response relationship between earlier school start times and shorter time in bed, primarily due to earlier wake times (P<.05). Start times after 8:30 am were associated with increased time in bed, extending morning sleep by 27-57 minutes (P<.05) when compared with teens with earlier school start times. CONCLUSION: Later school start times are associated with later wake times in our large, diverse sample. Teens starting school at 8:30 am or later are the only group with an average time in bed permitting 8 hours of sleep, the minimum recommended by expert consensus for health and well-being.
Authors: Vaka Rognvaldsdottir; Sigridur L Gudmundsdottir; Robert J Brychta; Soffia M Hrafnkelsdottir; Sunna Gestsdottir; Sigurbjorn A Arngrimsson; Kong Y Chen; Erlingur Johannsson Journal: Sleep Med Date: 2017-02-10 Impact factor: 3.492
Authors: Max Hirshkowitz; Kaitlyn Whiton; Steven M Albert; Cathy Alessi; Oliviero Bruni; Lydia DonCarlos; Nancy Hazen; John Herman; Eliot S Katz; Leila Kheirandish-Gozal; David N Neubauer; Anne E O'Donnell; Maurice Ohayon; John Peever; Robert Rawding; Ramesh C Sachdeva; Belinda Setters; Michael V Vitiello; J Catesby Ware; Paula J Adams Hillard Journal: Sleep Health Date: 2015-01-08
Authors: June C Lo; Su Mei Lee; Xuan Kai Lee; Karen Sasmita; Nicholas I Y N Chee; Jesisca Tandi; Wei Shan Cher; Joshua J Gooley; Michael W L Chee Journal: Sleep Date: 2018-06-01 Impact factor: 5.849