Associations of eHealth literacy and dietary diversity with depressive symptoms among patients with chronic diseases in rural Western China.

OBJECTIVE

The global prevalence of depressive symptoms has been increasing steadily. Both eHealth literacy and dietary diversity are closely linked to mental health. However, the mechanisms by which these factors jointly influence depressive symptoms remain unclear. This study aimed to investigate whether dietary diversity mediates the association between eHealth literacy and depressive symptoms among patients with chronic diseases in rural western China while also evaluating the interaction and combined effects of these two factors.

METHODS

This cross-sectional study utilized data from the 2024 Ningxia Rural Residents' Health Status and Health Service Utilization Survey. The final analysis included 2,655 patients aged 18 years and older with chronic diseases. Latent profile analysis (LPA) was employed to categorize eHealth literacy levels. A mediation analysis was performed to investigate the mediating role of dietary diversity in the relationship between eHealth literacy and depressive symptoms. To evaluate the interactive and joint effects of eHealth literacy and dietary diversity on depressive symptoms, multiplicative interaction models, additive interaction models, and multivariable logistic regression models were applied.

RESULTS

Using LPA, participants were classified into three groups on the basis of eHealth literacy: high (34.43%), medium (19.43%), and low (46.14%). Low eHealth literacy was linked to increased odds of depressive symptoms (OR = 1.64, 95% CI: 1.49 to 1.82), a relationship that diminished after adjusting for dietary diversity (OR = 1.53, 95% CI: 1.38 to 1.72). Dietary diversity served as a partial mediator in this association, explaining 18.79% of the total effect. A significant additive interaction was identified (RERI = 0.65; 95% CI: 0.12 to 1.19), whereas the results of the joint analysis revealed the lowest odds of depressive symptoms in the high-literacy/high-dietary-diversity group (OR = 0.17; 95% CI: 0.05 to 0.56).

CONCLUSIONS

Dietary diversity may partially mediate the association between eHealth literacy and depressive symptoms. A synergistic association exists between eHealth literacy and dietary diversity with respect to depressive symptoms. Within various eHealth literacy subgroups, dietary diversity is correlated with reduced odds of depressive symptoms, underscoring its potential significance for promoting mental health.