Associations of Sleep Quality with Cognitive Function in Chinese Older Adults: The Roles of Self-Efficacy and Depressive Symptoms

OBJECTIVE: To examine the associations among sleep quality, self-efficacy, depressive symptoms, and cognitive function in older adults, and to explore whether self-efficacy may be involved in the association between sleep quality and cognitive function and whether depressive symptoms may moderate this association. METHODS: A cross-sectional survey was conducted among 2,030 older adults in Ningxia, China. Sleep quality, cognitive function, self-efficacy, and depressive symptoms were assessed using validated instruments. After adjusting for age, gender, marital status, education level, residence, smoking and drinking status, living alone, exercise, hypertension, diabetes, and coronary heart disease, mediation and moderated mediation analyses were performed using the PROCESS macro. RESULTS: Significant correlations were observed among sleep quality, self-efficacy, depressive symptoms, and cognitive function. Self-efficacy showed a significant indirect effect in the association between sleep quality and cognitive function (B = -0.034, 95% CI: -0.048 to -0.022). In addition, depressive symptoms significantly moderated the association between self-efficacy and cognitive function (B = 0.009, p < 0.01). The magnitude of the indirect association between sleep quality and cognitive function through self-efficacy was stronger at higher levels of depressive symptoms. CONCLUSION: Poor sleep quality was associated with poorer cognitive function in older adults, and self-efficacy may be involved in this association. Depressive symptoms may further strengthen this indirect association. These findings suggest that sleep quality, self-efficacy, and depressive symptoms may all be relevant to cognitive health among older adults.