Objectively-measured sleep characteristics and the associated factors among rural and urban in-school Nigerian adolescents

Abstract

Purpose

Poor sleep is increasing worldwide but sleep studies, using objective measures, are limited in Africa. Thus, we described the actigraphy-measured sleep characteristics of Nigerian in-school adolescents and the differences in these sleep characteristics in rural versus urban-dwelling adolescents using actigraphy plus a sleep diary.

Methods

This comparative, quantitative study involved 170 adolescents aged 13–19 attending six rural and six urban schools in southwestern Nigeria. Participants wore actiwatches and filled sleep diaries concurrently for one week. We ran a mixed model analysis with each sleep characteristic as a dependent variable in each model and the fixed effects of age, weekday versus weekend, rural versus urban residence, sex, and religion.

Results

The adolescents were 54.1 % females with a mean age of 15.6 ± 1.3 years. Overall, adolescents’ mean bedtime was 22.50 ± 0.85, mean waketime was 5.73 ± 0.68 and mean total sleep time (TST) was 06.07 ± 0.95 h. On both weekdays and weekends, urban adolescents had significantly later bedtimes, earlier waketimes, shorter time-in-bed (TIB) and TST (all p < 0.05) while rural adolescents had lower sleep efficiency, more frequent awakenings and WASO (all p < 0.05). In mixed-model analyses, older adolescents had later bedtimes (p = 0.035) and shorter TST (p = 0.047), urban adolescents had later bedtimes, earlier wake times, shorter TIB and TST than rural adolescents (all p < 0.05), and on weekdays, all adolescents had earlier bedtimes, waketimes, shorter TIB and TST than on weekends (all p < 0.05).

Conclusion

Adolescents, especially the urban ones, had insufficient sleep with a catch-up-sleep on weekends. Multipronged interventions, including controlling causes of late bedtimes and delaying school start-times are needed to improve sleep, especially among older and urban adolescents.