Association Between Loneliness, eHealth Literacy, and Quality of Life Among Chinese Older Adults: Cross-Sectional Study.

Background: Loneliness is a growing public health challenge among older adults and is associated with a wide range of adverse health outcomes. The role of eHealth literacy in shaping the relationship between loneliness and quality of life remains unclear. Objective: This study aimed to examine the contributing role of eHealth literacy in moderating the associations between loneliness and quality of life among older adults. Methods: A community-based survey was conducted in 2025 among older adults aged 60 years or older living in northwestern China. A total of 2110 participants were included. Multiple linear regression and interaction models were used to assess associations and moderating effects. Sensitivity analyses were conducted by replacing the outcome variable with depressive symptoms and by performing stratified analyses to assess the robustness of the primary interaction findings. Results: Loneliness showed a consistent negative association with quality of life (β=-0.83, 95% CI -1.18 to -0.49; P<.001). Higher overall eHealth literacy was associated with better quality of life (β=0.41, 95% CI 0.35-0.47; P<.001). Interaction models indicated that higher eHealth literacy was associated with a steeper negative association between loneliness and quality of life (β=-0.04, 95% CI -0.08 to -0.002; P=.04). Sensitivity analyses produced similar results across alternative outcomes and subgroups. Conclusions: Higher loneliness was related to a poorer quality of life. Higher eHealth literacy was associated with a steeper negative association between loneliness and quality of life. These findings suggest that eHealth literacy may function as a double-edged sword in later life. Future research is needed to clarify the underlying mechanisms and to examine how digital health competencies interact with psychosocial vulnerability in shaping older adults' well-being.