Introduction: Early school timings along with delayed sleep phase syndrome causes adolescents to lose sleep during the school week. Studies have attributed insufficient sleep as one of the factors contributing to poor school performance of students. Sleep deprivation can impair memory and concentration, making it difficult for students to learn. Irritability, lack of self confidence and mood swings are common in teenagers, and sleep deprivation makes matters worse. This study compared the academic performance, sleep habits and mood changes in Indian student attending the same school in two different shifts.
Methods: A questionnaire-based cross sectional study was conducted among 834 students of VI to IX standard attending different shifts [Shift I (7:00 am to 1:10 pm) and Shift II (11:30 am to 6:00pm)].The questionnaires evaluated the students for their sleep pattern, duration, napping, quality of sleep and mood. Daytime sleepiness was scored using the Epworth Sleepiness Scale. Performance was calculated by their percentages in respective subjects and a total score was taken for their overall performance during the academic session.
Result: Baseline characteristics of both the groups were comparable with mean age of 12.9±1.33 (shift I) & 12.9±1.21 (shift II). Shift II students had significantly greater total sleep time with only 19 % of them reporting sleep deprivation (total sleep time<8hrs) as compared to 58% of shift I. Shift I students reported daytime tiredness in 8.4%, napping in 51.7% and sleep awakenings at night in 58.1% which was significantly more as compared to Shift II students. Sleepiness in prelunch classes (P = 0.001) as well as consumption of caffeine/tea (P = 0.0001) was also more in Shift I. Overall performance of shift II students was better than shift I, with students getting significantly better grades in English (P = 0.001) and Mathematics (P = 0.003).
Conclusion: This study demonstrated that early school timings contribute significantly to sleep deprivation among adolescents, leading to daytime sleepiness and poorer academic performance. Apart from delayed sleep phase syndrome, other social engagements may be the contributory factors for the late bed timings leading to sleep deprivation in morning shift students. Further studies, involving students of different socioeconomic group of different cities, are recommended to find the various factors and the extent to which each of them are responsible for change in sleep habits affecting mood and academic performance.
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