JMIR Publications

ABSTRACT

Background:

The elderly demographic in China is undergoing a consistent increase, with a concomitant increase proportion of elderly in self-care functional disability. Among older people, the duration of sleep is a significant factor associated to health status, however, findings from previous researches have not been entirely consistent about the correlation between sleep duration and functional disability.

Objective:

To investigate the association between sleep duration and functional disability among the elderly aged 65 years and older in China.

Methods:

This is a nationally representative across-section study. Participants were aged 65 and above Chinese adults drawn from the 2018 survey of the China Health and Retirement Longitudinal Study (CHARLS). The duration of sleep per night obtained from face-to-face interviews. Functional disability was defined as a difficulty in performing activities of daily living (ADL) or instrumental activities of daily living (IADL). The association between sleep duration and functional disability was assessed by multivariable generalized linear model. The dose‐response relationship between sleep duration and functional disability was analyzed using restricted cubic spline function.

Results:

Of the 19 816 respondents, a total of 5 519 subjects were included in this study. The age of the subjects was (73.67±0.09) years, including 3 048 (55.23%) females. The prevalence of functional disability was 50.73% (2 800/5 519). After adjusted for potential confounders, individuals reporting shorter sleep durations (≤ 4, 5, 6 hours) or longer sleep durations (8, 9, ≥ 10 hours) per night exhibited a notably elevated risk of functional disability compared to the reference group (7 hours) (P < 0.05). Further analysis suggested a U-shaped association between sleep duration and functional disability. When sleep duration fell below 7 hours, increased sleep duration was associated with a significantly lower risk of functional disability (OR, 0.85; 95% CI, 0.79–0.91; P < 0.001), and the risk of functional disability would increase facing prolonged sleep duration (OR, 0.85; 95% CI, 0.79–0.91; P < 0.001).

Conclusions:

Shorter and longer duration was associated with a higher risk of functional disability among the aged 65 and above Chinese adults. Future studies are needed to explore intervention strategies about sleep duration especially focus on functional disability.