Association Between Digital Literacy and Physical and Mental Health Among Middle-Aged and Older Adults: The Mediating Effect of Social Interaction-A Cross-Sectional Study Based on CHARLS 2020

IntroductionCurrently, middle-aged and older adults face the compounded challenges of a dual "digital divide" and "health divide."MethodUsing data from the 2020 China Health and Retirement Longitudinal Study (CHARLS), this study constructed a digital literacy index via polychoric confirmatory factor analysis (Polychoric CFA). Ordered logit (ologit) models were employed to estimate the associations between digital literacy and physical and mental health among middle-aged and older adults. The Karlson-Holm-Breen (KHB) method with 1,000 bootstrap resamples was utilized to examine the mediating effect of social interaction in these relationships. Additionally, heterogeneity analyses across gender and household registration (hukou) status were conducted.ResultsThe findings reveal that digital literacy is significantly and positively associated with both the physical health and mental health of middle-aged and older adults. After incorporating social interaction, the indirect effect remains statistically significant, indicating that social interaction serves as an important pathway linking digital literacy to physical and mental health. Heterogeneity analysis further indicates gender-specific patterns: digital literacy maintains a significant positive association with physical health among men, but this association is not statistically significant among women; conversely, digital literacy exhibits a significant positive association with mental health among women, whereas this association does not reach statistical significance among men. Regarding household registration (hukou), formal inter-group difference tests reveal no statistically significant differences, suggesting that the positive associations between digital literacy and health outcomes are highly consistent and generalizable across urban and rural middle-aged and older populations.ConclusionBy disentangling the transmission pathway of "digital technology→social interaction→health outcomes," this study provides empirical evidence for developing countries to address digital health inequalities against the backdrop of population aging. We propose the following policy recommendations: (1) Advance national initiatives to enhance digital literacy among middle-aged and older adults, lower technological barriers, and help older cohorts overcome obstacles to digital technology adoption; (2) Improve the accessibility and age-friendliness of the digital society, with an emphasis on age-adapted product interfaces and community-based digital support networks; and (3) Formulate targeted health interventions for multiply vulnerable subgroups to enhance the precision and efficacy of public health policies.