Our study provides a subjective sleep profile of a large British population–based cohort.
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The reported time in bed (TIB) was more than 1.5 h longer than sleep duration.
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All sociodemographic factors varied with TIB and sleep duration.
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Sleep proportion may be a useful indicator of sleep patterns in this population.
Abstract
Objectives
Sleep patterns have been linked to various health outcomes, but sleep patterns in the British population have not been extensively reported. We aimed to describe the sleep characteristics reported by the European Prospective Investigation of Cancer (EPIC)-Norfolk participants, with a particular emphasis on the comparison of measures of sleep quantity.
Methods
From 2006 to 2007, a total of 8480 participants aged 45–90 years reported sleep timing, nighttime sleep duration, and sleep difficulties. Time in bed (TIB) was calculated from the difference between rise time and bedtime, and sleep proportion was defined as the ratio of sleep duration and TIB.
Results
On average, the reported TIB was more than 1.5 h longer than sleep durations. Compared to men, women spent 15 min longer in bed, but they slept for 11 min less and reported more sleep difficulties. In multivariate analysis sleep duration and TIB varied with socioeconomic factors, but sleep proportion was consistently lower among women, nonworkers, and older individuals, as well as those who were widowed, separated, or divorced; those who reported sleep difficulties and more frequently used sleep medication; and those who had lower education, poorer general health, or a major depressive disorder (MDD).
Conclusions
Self-reported sleep duration and TIB have different meanings and implications for health. Sleep proportion may be a useful indicator of sleep patterns in the general population.
