Ageing is an important issue that cannot be ignored in modern Chinese society. The population aged 60 and over exceeds 260 million, accounting for 18.70%. The elderly population in China is expected to exceed 300 million and step from mild ageing into moderate ageing before 2025. As an important basis for ensuring the daily life and social activities of this large group, improving the health status of the elderly is a very critical issue. Actively coping with population ageing and improving the health status of the elderly has become a national strategy for every country. Accordingly, the factors affecting the physical and mental health of the elderly have always been the focus of scholars' research. The theory of health production proposed by Grossman[1] indicates that health may be affected by health care, income level, lifestyle, education level, and living environment, amongst others. Amongst all these factors, socioeconomic status (SES) has received increased attention in recent years.
SES is defined as an individual or group's position within a hierarchical social structure, reflecting the social class and status of different groups[2, 3]. It is a comprehensive indicator of income level, education level, occupational status, and wealth, and these resources may enable people to achieve certain goals[4]. It is also an important indicator to measure and predict people's behaviour[5]. Research on the relationship between SES and health could be traced back to the 1950s. Most early studies have focused on the role of structural factors, i.e., SES affects personal health through health literacy, accessibility of medical services, and living environment[6]. In recent years, the influence of SES on health has been extended to lifestyle factors, social psychological factors, and other aspects. Marmot[7] found that SES affects health through social gradient, income, social exclusion, education, psychological status, and other factors. People with lower SES have lower autonomy to work, corresponding to easier generation of pressure and negative emotions. Cristine et al.[8] believed that people with adverse SES are more likely to fall into a negative environment, have negative emotions, and suffer from potential stress, all of which have a negative impact on health. SES also reportedly affects health through interaction across different factors[9]., including exposure to environmental toxins, air and water pollution, ambient noise, employment in jobs with a high risk for injury or disability, lack of health insurance or access to high quality and preventative health care, and poor nutrition, as well as adverse health behaviours such as smoking, excessive alcohol intake, sleeping patterns, and physical inactivity[10–12]. Warr[13] believed that SES often affects individual lifestyle and health status through the joint action of local culture, neighbourhood environment, or social and psychological factors. For example, people with high psychological stress and negative emotions are more likely to smoke and drink alcohol, thereby affecting their health. The research above has revealed the close relationship of the SES with the physical and mental health of the elderly, but the specific impact mechanism and path remain unclear.
The Anderson model[14, 15] indicates that predisposing factors and enabling factors affect health outcomes through health behaviours. As an important element of predisposing factors, SES has also been shown to have a significant impact on health outcomes. Health behaviours include personal self-care and health service utilisation. In self-care behaviours, the social participation behaviours of the elderly are gradually receiving increased attention, which may play an important role in the process by which SES affects health outcomes. No clear and unified definition of social participation exists[16]. The social participation of the elderly is generally believed to be primarily reflected in three aspects. First, from the perspective of role intervention, it emphasises that elderly people play a meaningful social role in leisure or productive activities[17]. This definition reflects the identity and role attribution of the elderly in the process of social participation. Second, from the perspective of social interaction[18], it emphasises interaction with people other than spouses in formal or informal occasions[19]. This definition usually regards social communication and interaction as the core components of social participation of the elderly. Third, from the perspective of function exertion, social participation of the elderly is defined as their meaningful participation in social and productive activities[20] or as engaging in activities involving personal actions and contributions to others. Many studies have shown that social participation can significantly affect the physical and mental health of the elderly, and that more social participation can significantly reduce the risk of death or disability[21–24]. It is believed to be a crucial component of positive ageing[25]. Activities such as visiting relatives and friends or chatting with friends and relatives are related to longevity[26]. Some studies have also revealed that social participation can effectively reduce the risk of depression in the elderly, and that active social participation can significantly prevent and alleviate depression and improve their mental health[27–30]. Based on the activity theory, the elderly could find their identities and meaning through social roles, leading to vitality in their lives[31]. At the same time, some scholars have found that factors such as income, occupation, and education can significantly affect the level of individual social participation[32, 33].
Therefore, based on the Anderson model, this study aimed to determine the impact mechanism of SES on the physical and mental health of the elderly from the perspective of social participation of the elderly, as well as to explore the mediating effect of social participation. Based on existing research results, the hypotheses of this article are as follows.
Hypothesis 1
Higher SES of the elderly has a positive impact on their social participation.
Hypothesis 2
Greater social participation of the elderly has more positive effects on their physical and mental health.
Hypothesis 3
Higher SES of the elderly has more positive effects on their physical and mental health.
Hypothesis 4
The degree of social participation of the elderly exerts a mediating effect on the path through which the social and economic status of the elderly affects physical and mental health.