Sleep behavior of South African adolescents

To survey a large group of South African adolescents about their sleep behavior, daytime behaviors, and morning alertness as compared to those of other teenagers worldwide.

Subjects completed a questionnaire about their sleep habits and daytime behaviors on the previous day, and subjective morning alertness at the time of completing the questionnaire.

Four secondary schools in Johannesburg, South Africa on mid-week mornings.

825 secondary school students volunteered for this study.

N/A.

The students, (16+/-1 years), 61% female, reported significantly less time in bed (p<0.001) on a school night (453+/-70 minutes), compared to weekend nights (476+/-128 minutes). On the school night, they reported a mean sleep onset latency of 17 minutes, with 45% of the sample falling asleep in less than ten minutes. Short sleep onset latency and short in-bed wakefulness both were positively related to a high sleep efficiency and subjective sleep quality. On the previous day, 72% of the adolescents had consumed caffeinated beverages and 56% had exercised, but these behaviors did not significantly influence their nighttime sleep. The majority (77%) of students had napped the previous day and 8% had taken medication to fall asleep that night. 40% of the students felt that they could fall asleep mid-morning, if given the chance, but their sleepiness was independent of their nighttime sleep quality or duration.

Similarly to teenagers around the world, South African adolescents get insufficient sleep during the week, which they attempt to compensate for on the weekends. A large proportion of the students are also sleepy during the school day, which may influence their academic performance.