Sleep-wake patterns and disturbances in Portuguese primary school children: a comparison between 1995 and 2016.

Abstract

It is often assumed sleep duration has decreased and sleep schedules have delayed over the last decades, as society modernized. We aimed to investigate changes in the sleep patterns of school-age children over time. We compared the sleep timings, durations, and disturbances of primary school-age children in 1995 and roughly two decades later, in 2016. Data from 666 children attending the 3rd and 4th grades of basic education were combined from two different cross-sectional school-based studies conducted within the same educational region of mainland Portugal using the same parent-report questionnaire (Children's Sleep-wake Patterns Questionnaire). Mean sleep duration did not differ significantly between the two time points (schooldays: t = .118, p = .906; free days: t = 1.310, p = .191), albeit the percentage of children sleeping the recommended number of hours decreased significantly in 2016 when compared to 1995 (schooldays: χ2 = 4.406, p = .036; free days: χ2 = 16.859, p < .001). Wake-times advanced on free days in 2016. Difficulties on settling to sleep alone and returning to sleep were more prevalent in 2016, as well as fearing the dark and needing lights on or parent's presence to fall asleep. Sleep onset-related disturbances appear to have increased from 1995 to 2016. One possible explanation for this increase might be the change in parental practices preventing children from learning to fall asleep autonomously.