Peer health literacy level and health literacy among school-aged children and adolescents: a multilevel moderated mediation model of internet health information acquisition

Background: Health literacy is a critical determinant of health outcomes among school-aged children and adolescents. Although peer environments are known to shape adolescent health-related behaviors, their association with health literacy—particularly through internet health information acquisition—remains underexplored in multilevel settings. Objective: This study examined the association between peer health literacy context and health literacy among Chinese school-aged children and adolescents, testing the mediating role of internet health information acquisition and the moderating effects of contextual factors (e.g., perceived teacher support, policy environment, economic status) within a multilevel moderated mediation framework. Methods: We analyzed cross-sectional data from 3307 participants in Shaanxi Province, China, collected in 2021. Multilevel mediation and moderation analyses used the Monte Carlo method with 5000 simulations. Results: Peer health literacy context was negatively associated with health literacy (β = – 17.513, P < 0.001). Internet health information acquisition showed a significant negative indirect pathway at the group level (β = – 0.052, 95% CI: –0.081, –0.027). Left-behind status, economic indicators, and policy variables significantly moderated the mediating pathway. Conclusions: A higher peer health literacy context was associated with lower individual health literacy, and this pattern was partially explained by internet health information acquisition. Contextual factors at the school, policy, and economic levels play significant moderating roles in this pathway. These findings suggest that adolescent health literacy should be understood not only as an individual competence but also as a process shaped by peer context and broader ecological environments.