Original articleSocial determinants of self-reported sleep problems in South Korea and Taiwan☆,☆☆
Introduction
A single-day survey performed in 10 industrialized countries estimated that one in four individuals does not sleep well [1]. Insomnia, one of the most frequently reported health problems in the general population, has drawn public attention and, in response to public concern, many scientific studies have been conducted on the etiology of insomnia. Previous reports generally agree that psychological disorders [2] and physiological illnesses, including obstructive sleep apnea syndrome [3], obesity [4], and cardiovascular malfunction [5], are closely related to insomnia.
In addition, several epidemiological studies have suggested that insomnia is associated with social factors including ethnicity [6], gender (i.e., being female), age (i.e., older age) [7], [8], [9], [10], [11], [12], and socioeconomic status (i.e., low income or low educational attainment) [13], [14]. However, the majority of these studies were conducted in Western countries and appropriate empirical evidence is lacking for Asia. Furthermore, the majority of these epidemiological studies also failed to demonstrate the mechanisms underlying the reported associations. Nevertheless, two recent studies have suggested the mechanism by which socioeconomic status affects sleep problems. Moore et al. [15] reported that higher education was associated with higher income and that higher income was associated with better physical and psychological health. Van Cauter and Spiegel [16] reported that low socioeconomic status was associated with diminished opportunities to obtain sufficient sleep or with environmental conditions that compromise sleep quality.
Likewise, in consideration of the relationship between sleep problems and social factors, we focused particularly on social capital as one of the factors mediating sleep problems. Social capital refers to social connections within and between human networks, and many epidemiological studies conducted during the past few decades have suggested that this factor positively affects both health and well-being [17], [18], [19], [20], [21], [22]. Social capital operates through civil society, which consists of “private organizations that are formed and sustained by groups of people acting voluntarily and without seeking personal profit to provide benefits for themselves or for others” [21], [23], [24]. These voluntary associations also connect people with one another, build trust and reciprocity, and consolidate society on the basis of a sense of altruism rather than obligation. We assumed that people become socially isolated under circumstances in which social capital is less available and that such individuals are at increased risk for insomnia because of their limited access to resources such as medical care, information, and emotional support.
Thus, the purpose of this study was twofold: (1) to investigate the social determinants of sleep problems in two northeastern Asian countries, South Korea and Taiwan; and (2) to clarify whether social capital is associated with sleep problems.
Section snippets
Population and samples
Data were collected from cross-sectional surveys conducted in South Korea and Taiwan in 2003 as part of “A Study of Statistical Science on Health and Culture.” These data have been reported in part elsewhere [25], but here we investigate a new hypothesis using data that were not previously examined. The target populations were adults (aged ≥20 years) residing in each country. The survey involved a face-to-face interview by well-trained interviewers using a semistructured questionnaire that was
Results
The number of valid questionnaires returned was 1007 in South Korea (complete sample) and 785 in Taiwan (response rate=44%). Table 1 shows the basic characteristics of subjects in relation to self-reported sleep symptoms. The prevalence of self-reported sleep problems was 8.4% (5.4% for DIS, 5.1% for DMS, and 4.4% for EMW) in South Korea, compared to 9.3% (6.8% for DIS, 3.6% for DMS, and 3.8% for EMW) in Taiwan. Regardless of country, people who were female, older and with lower income or
Discussion
This study sought to assess the social determinants of self-reported sleep problems in South Korea and Taiwan. Sleep problems in these two northeastern Asian countries were associated with demographic characteristics, socioeconomic factors, and social support. We discuss the results of the present study in light of its strengths and limitations below.
A meta-analysis showed that women were more likely to report insomnia than were men [7], [6], but the majority of the individual studies included
References (34)
- et al.
How do individuals sleep around the world? Results from a single-day survey in ten countries
Sleep Med
(2005) - et al.
Insomnia: Epidemiology, characteristics, and consequences
Clin Cornerstone
(2003) - et al.
The influence of age, gender, ethnicity, and insomnia on Epworth Sleepiness Scores: A normative US population
Sleep Med
(2006) - et al.
Prevalence of insomnia and associated factors in South Korea
J Psychosom Res
(2002) - et al.
Does social capital enhance health and well-being? Evidence from rural China
Soc Sci Med
(2007) - et al.
Perceptions of social capital and the built environment and mental health
Soc Sci Med
(2006) - et al.
Association of sleep-disordered breathing, sleep apnea, and hypertension in a large community-based study: Sleep Heart Health Study
JAMA
(2000) - et al.
Incidence of sleep-disordered breathing in an urban adult population: The relative importance of risk factors in the development of sleep-disordered breathing
JAMA
(2003) - et al.
Sleepiness in obstructive sleep apnea: A harbinger of impaired cardiac function?
Sleep
(2006) - et al.
Sex differences in insomnia: A meta-analysis
Sleep
(2006)
How age and daytime activities are related to insomnia in the general population: Consequences for older people
J Am Geriatr Soc
Can social factors explain sex differences in insomnia? Findings from a national survey in Taiwan
J Epidemiol Community Health
Sleep complaints and depression in an aging cohort: A prospective perspective
Am J Psychiatry
Prevalence and risk factors of insomnia in community-dwelling Chinese elderly: A Taiwanese urban area survey
Aust N Z J Psychiatry
Epidemiology of insomnia in Korean adults: Prevalence and associated factors
J Clin Neurol
Insomnia and health problems in Canadians
Sleep
Socioeconomic status and health: The role of sleep
Psychosom Med
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Competing interests: The researchers have no financial conflicts of interest.