Highlights:
- Social capital was associated with better functional and emotional health, which were consistent between men and women and between rural and urban respondents.
- Functional and emotional health was mediated by social capital and was better for population with strong socioeconomic status.
- Requisite of future interventions to reinforce social capital status of ageing population.
China has the largest and fastest-growing aging population in the world [1]. Population aging is driven by improvements in longevity and health. China’s life expectancy at birth increased from 71.4 years old in 2000 to 76.5 years old in 2016, while the healthy life expectancy (HALE) at birth increased from 64.8 to 68.7 (64.8 in 2000 and 68.7 in 2016) [2]. However, the increased gap between life expectancy and HALE indicates a rising need for care. The provision of care is likely to be eroded by social and economic transitions which are changing traditional care arrangements for older people in China. Thus, both research and policies are interested in identifying resources that can contribute to extend the number of years associated with good health.
Functional and mental health are core elements of healthy aging. Recent studies reported poor functional and mental health among Chinese elders. According to China Health and Retirement Longitudinal Study (CHARLS), 38.1% of 60 or above aged people had difficulties in at least one activity of daily living (ADL) or instrumental activity of daily living (IADL). Among the 38.1%, almost 23.8% of these elders need help in the daily activities [3]. In addition, both depressive symptoms and diagnosable major depressive disorder were prevalent among elders in China. According to a meta-analysis, the pooled prevalence of depressive symptoms in older adults in China was 23.6% [4]. According to the China Mental Health Survey, the 12-month prevalence of major depressive disorder was 3.0% among 65 or above aged people [5]. According to an earlier study, the 1-month prevalence of major depressive disorder was 3.8% among 55 or above aged people [6]. The treatment rate among older adults with depressive symptoms or major depressive disorder was extremely low [7–8].
The importance of social capital has gained recognition in aging studies associated with risk factors and protective factors in China, which primarily focused on the central role of family. Social capital is a multidimensional concept, and there are two main schools of thoughts regarding its definition. The first school is influenced by Putnam who defined social capital as “features of social organization such as networks, norms and social trust that facilitate coordination and cooperation for mutual benefit [9].” The second school draws on the work of Bourdieu who defined social capital as “the aggregate of the actual or potential resources which are linked to possession of a durable network of more or less institutionalized relationships of mutual acquaintance and recognition [10].” The former conceives social capital as a social feature while the latter focuses on individuals’ resources as a result of their social networks.
Though there is no consensus about which methods are the most appropriate to measure this multidimensional concept [11–13], the measurements should consider cultural factors and the characteristics of the society [14]. Most of the previous literature studies on Chinese elders has focused on individual social capital, and some further emphasized the “structural/cognitive” distinction of social capital. Structural social capital subsumes behavioral manifestations of social capital, such as participation in formal associations, while cognitive social capital encompasses attitudinal manifestations, namely trust and reciprocity between individuals [15]. Thus, social participation (e.g., the number of organizations to which the respondent belongs) and trust were often used as proxy measures for social capital [16–18].
The relationship between social capital and health has been established [19]. In context to aging, it was observed that high levels of social capital enable older adults to maintain favorable mental and physical health [20]. However, research on social capital and health among elders in China is relatively limited. Social capital was found to be positively associated with health-related quality of life [12], self-reported health [17], and mental health (e.g., cognitive function) [21], whereas, negatively associated with depressive symptoms [18]. The associations between social capital and health might differ across gender and urban status [22]. Sun et al found stronger association between individual social capital and mental health among women than men [12]. Norstrand et al [22] found that social capital was significantly associated with physical and emotional health among urban elders, but no significant associations between social capital measures and health among rural elders was found. However, previous studies have mixed findings on the impacts of the structural and cognitive dimension of social capital [23], and were mostly localized. None of the previous study have examined the relationship between social capital and elder’s functional health.
To cover the dearth of knowledge, we examined the relationship between structural social capital and functional and emotional health in this study, using a nationally representative sample of elders in China. We hypothesized that having more structural social capital can increase the quality of functional and mental health, after controlling other sociodemographic factors. Functional and emotional health were better for those with higher socioeconomic status (SES), mediated by social capital.