Study Objectives: To assess the relationship between sex and the development of sleep patterns in adolescents from grade 7 to 12. Methods: We analyzed longitudinal data from annual school-based assessments of sleep habits among secondary school students in northern Taiwan. Measures of sleep patterns included sleep length on weekdays and weekends as well as weekend-weekday difference (WndD), defined as the discrepancy in the time in bed (TIB) between weekdays and weekends. Growth curve models were used to assess sex differences in sleep patterns. Associations between other covariates and sleep patterns were also explored. Results: We found shorter weekday TIB in girls compared to boys at all time points. In contrast, girls had longer weekend TIB than boys over time except in the 12th grade. WndD was also longer in girls than boys. All interaction terms between sex and time were insignificant, indicating that developmental change across time was not statistically different for boys and girls. Several other factors, namely parental education, pubertal development, self-perceived health, weight status, depressive symptoms, academic stress, infrequent exercise, and substance use were also found to be associated with sleep patterns. Conclusions: Our findings show a sex difference in TIB both on weekdays and weekends. No sex difference was found in the development of sleep patterns over time.
