Social determinants of self-reported sleep problems in South Korea and Taiwan

Objective: To clarify the social determinants of insomnia in South Korea and Taiwan. Methods: Cross-sectional surveys were conducted in South Korea (n=1007) and Taiwan (n=785) in 2003. Nationwide samples of people completed a structured questionnaire, based on face-to-face interviews. Outcome measures were self-reported sleep problems, defined by at least one of three sleep symptoms on a nightly basis for more than 2 weeks: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and early morning waking (EMW). Explanatory variables investigated were demographic characteristics (gender, age), socioeconomic factors (income, education), and social capital, including norms of reciprocity, interpersonal trust, civic association, and social support (i.e., the availability of persons to consult regarding personal problems and important matters). Results: The prevalence of sleep problems was 8.2% in South Korea and 9.3% in Taiwan. Stepwise logistic regression showed that, in South Korea, sleep problems were significantly associated with increasing age (P<.05), low income (P<.01), and having few persons with whom to consult compared to having a spouse/partner (P<.05); in Taiwan, sleep problems were significantly associated with being female (P<.05), increasing age (P<.001), and having family members vs. a spouse/partner to consult (P<.05). Conclusion: Self-reported sleep problems in two northeast Asian countries were associated with certain demographic characteristics and socioeconomic factors, which is consistent with previous results in Western countries. In addition, the results of this study suggested that sleep problems may also be associated with social support. (C) 2010 Elsevier Inc. All rights reserved