RESUMEN
BACKGROUND: Sleep quality has been widely studied among western countries. However, there is limited population-based evidence on insomnia in Chinese adult populations, especially in middle-aged and older adults. The aims of present study are to (1) examine the prevalence of poor sleep among Chinese middle-age and older adults, (2) compare the Pittsburgh Sleep Quality Index (PSQI) seven domain scores across different physical health statuses, (3) explore factors associated with insomnia. METHODS: A cross-sectional survey was conducted using a multi-instrument questionnaire. In total, 1563 residents aged 45 or older in the community were interviewed. The Chinese version of the PSQI was used to assess sleep quality while poor sleep was defined as a total PSQI score >5. Socio-demographic, lifestyle and physical health data were also collected. RESULTS: The prevalence of poor sleep among adults aged over 45 years was 20.67 %. Clusters logistic regression analysis identified that migrant workers, single marital status, lower education level, no physical exercise, illness within 2 weeks, and a higher total number of chronic diseases contribute to increased risk of poor sleep (P < 0.05). Among three clusters, physical health has the biggest independent contribution on sleep quality. CONCLUSIONS: Our results indicated that poor sleep was common in middle-aged and older adults. It was associated with identity of migrant worker, education level, exercise, illness within 2 weeks and number of chronic disease. Being ill within 2 weeks and having more chronic diseases were the major physical health-related factors contributing to poor sleep in the middle-aged and older people. Physical health may be a major determinant in sleep quality.