Association Between Health Literacy and Salt-Related Knowledge, Attitudes, and Practices: A Path Analysis of Indirect...

Background: Reducing dietary salt intake is a global public health priority. However, empirical evidence is needed to clarify whether higher levels of health literacy (HL) and eHealth literacy (eHL), together with the use of diversified information dissemination channels, are positively associated with better salt-related knowledge, attitudes, and practices (KAP). This study examined the indirect associations via eHL and the number of sources of salt-reduction information (NSSI) in the relationship between HL and salt-related KAP. Methods: A cross-sectional survey was conducted from 2022 to 2023 using multistage stratified random sampling among residents aged 15-69 in 22 counties/districts of Jiangxi Province, China. Data on sociodemographic characteristics, HL, eHL, NSSI, and salt-related KAP were collected through face-to-face household interviews using a standardized electronic questionnaire system. Spearman correlation analysis and multiple linear regression were applied to assess associations among HL, eHL, NSSI, and salt-related KAP. Path analysis was employed to evaluate the indirect associations between HL and salt-related KAP via eHL and NSSI. Results: A total of 5396 residents participated, of whom 51.50% were male. Participants aged 15-34, 35-54, and 55-69 years accounted for 13.10%, 42.96%, and 43.94% of the sample, respectively. After adjustment for covariates, individuals with adequate HL, adequate eHL, and a greater NSSI had significantly higher total salt-related KAP scores (p < 0.001). In the path analysis, the standardized direct association of HL with the total salt-related KAP was 0.229 (p < 0.001). The standardized indirect associations via NSSI and eHL were 0.089 (95% CI: 0.069 to 0.111, p < 0.001) and 0.057 (95% CI: 0.033 to 0.089, p < 0.001), respectively, accounting for 23.73% and 15.20% of the total association. Conclusions: High levels of HL and eHL, together with increased exposure to multiple salt-reduction information sources, are associated with improved salt-related KAP. Both eHL and NSSI partially explain the association between HL and salt-related KAP. Future salt-reduction interventions should integrate conventional health education with mobile health technologies to expand information dissemination channels and support sustained salt-reduction behaviors.