Sleep patterns of urban school-going adolescents

OBJECTIVE: To analyze the variance in sleep habits of adolescents of different high school Grades in urban India. DESIGN: Cross-sectional questionnaire-based study. SETTING: Community based school survey in an urban setting. SUBJECTS: School going adolescents from 9th to 12th Grades. METHODS: A total of 1,920 adolescents aged 12-18 years were included. The questionnaire contained questions related to sleep habits. Each question was explained to the participants and their responses were noted. Outcome parameters were total sleep time in a day, time to go to bed and wake up-time, sleep latency, nocturnal awakenings (duration, frequency per night and nights per week), wake-time after sleep onset, wake time after sleep offset, sleep efficiency, quality of sleep, daytime napping (duration and frequency), and sleepiness during the day. RESULTS: Mean age of the adolescents included in this study was 15.1 years and mean total sleep time was 7.8 hr/day. Adolescents of higher Grades had lesser total sleep time (9th=8 hours; 10th=7.7 hours; 11th=7.9 hours; 12th=7.6 hours; P=0.001), and more frequent nocturnal awakenings (9th=35.9%; 10th=44.7%; 11th=40.3%; 12th=28.3%; P=0.001). Daytime leg pain ( 9th=14.4%; 10th=18.4%; 11th=6.1%; 12th= 21.8%; P=0.01), daytime napping (9th=47.6%; 10th=50.4%; 11th=61.8%; 12th=69.8%; P=0.001), and daytime sleepiness (9th=37.2%; 10th=39.1%; 11th=39.7%; 12th=54.2%; P=0.001) increased progressively among higher Grades. Adolescents in higher Grades were more prone to not follow their weekly schedule on week-ends (P= 0.001). Sleep debt of approximately one hour per day was seen in all adolescents, and progressed with higher Grades. CONCLUSION: Adolescents of higher Grades had lesser sleep time, and frequent awakenings; suffered daytime leg pain, and felt sleepy during the day. These factors suggest increasing sleep deprivation among higher Graders.