The Chain Mediation Role of Self-Efficacy, Health Literacy, and Physical Exercise in the Relationship Between Internet Use and Older Adults' Health: Cross-Sectional Questionnaire Study.

Background: With the widespread use of the internet, the number of older internet users is rapidly increasing. However, the role of individual factors such as self-efficacy, health literacy, and physical exercise in the chain of influence between internet use and the health of older adults is unclear.

Objective: On the basis of the media effects theory and the health belief model, we aimed to explore the relationship between internet use and self-rated health among Chinese older adults. We also analyzed the mediating roles of self-efficacy, health literacy, and physical exercise and examined how these mediating effects varied by sex, residence, and per capita monthly household income groups. In addition, we investigated the moderating effect of education level.

Methods: We included 1147 participants aged ≥60 years from the 2021 Psychology and Behavior Investigation of Chinese Residents project in this study. Using a combination of multiple linear regression and bootstrap testing, we constructed a chain mediation model and a moderated chain mediation model to examine how internet use affects older adults' health through self-efficacy, health literacy, and physical exercise. In addition, we explored the marginal effects of education level within each mediation pathway.

Results: Internet use significantly improved the self-rated health of older adults (B=2.183; P<.001), and this improvement was exclusively mediated by self-efficacy (B=0.502; P<.001), health literacy (B=5.415; P<.001), and physical exercise (B=3.449; P<.001). These three factors could act as independent mediators or form sequential chain mediation pathways. In heterogeneity analysis, the total indirect effects were more pronounced among female participants (B=1.965; P<.05) and individuals with middle (B=1.971; P<.05) to high (B=2.710; P<.05) income levels. Furthermore, education level moderated the relationships between internet use and self-efficacy (B=0.452; P=.003) and between internet use and self-rated health (B=1.284; P=.01). This suggests that the positive influence of internet use on self-rated health was more pronounced among older adults with higher education.

Conclusions: The findings of this study suggested that internet use can positively influence older adults' self-rated health through the chain mediated effects of self-efficacy, health literacy, and physical exercise. This chain mediated effect was more pronounced among those with higher levels of education. In the future, efforts should be made to promote internet use among older persons by developing age-friendly digital platforms and expanding digital training and health education. Moreover, older persons should be encouraged to participate in volunteer activities to increase their self-efficacy and improve their health.