Insufficient sleep and sociodemographics
We found a significant age effect; the level of insufficient sleep gradually decreased with age, with the highest levels in younger adults and the lowest levels in the oldest adults, replicating our previous finding (29). It is plausible that persons in the oldest age group may report the highest sleep quality because those with poor sleep quality associated with chronic illnesses may have died earlier or were unable to complete the survey.
Insufficient sleep was more common among women. This finding is in line with the majority of other studies (29–34), reporting that women have a higher need for sleep and more sleep disturbances than men. In our study, increasing household size was also associated with increased level of insufficient sleep. Even though we did not look at interaction between gender and household size, we speculate that increasing household size probably impacts women’s sleep more, as women are the primary caregivers in most families.