Study objectives: To examine factors associated with self-reported sleep quality and duration among very old adults in China.
Design: Cross-sectional analysis of the 2005 wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS).
Setting: In-home interview with older adults in 22 provinces in mainland China.
Participants: A total of 15,638 individuals aged 65 and older (5,047 aged 65-79, 3870 aged 80-89, 3927 aged 90-99, and 2794 aged 100 and older, including 6688 men and 8950 women).
Measurements and results: Two self-reported sleep questions together with numerous sociodemographic and health status measures were used in this study. Sixty-five per cent of Chinese elders reported good quality of sleep. The average number of self-reported hours of sleep was 7.5 (SD 1.9), with 13.1%, 16.2%, 18.0%, 28.0%, 9.2%, and 15.5% reporting < or = 5, 6, 7, 8, 9, and > or =10 hours, respectively (weighted). Multivariate analyses showed that male gender, rural residence, Han ethnicity, higher socioeconomic status, and good health conditions were positively associated with good quality of sleep. All other factors being equal, octogenarians, nonagenarians, and centenarians were more likely to have good sleep quality than the young elders aged 65-79. Elders with poorer health status or older age were more likely to have either relatively shorter (< or = 6 h) or longer (> or = 10 h) sleep duration. Married elders were more likely to have an average duration between these two values. Except for some geographic variations, associations between all other factors and sleep duration were weak compared to the effects of health.
Conclusions: Age and health conditions are the two most important factors associated with self-reported sleep quality and duration. Good quality of sleep among long-lived old adults may have some implications for achieving healthy longevity.