Health literacy as a mediator of the relationship between socioeconomic status and health: A cross-sectional study in a population-based sample in Florence

Background Health literacy(HL) has recently been proposed as a potential mediator in the pathway through which socio-economic status(SES) affects health. However, empirical research investigating the contribution of HL in this relationship remains scarce. This study investigated whether functional HL mediates the association between SES and self-reported health(SRH) in an adult population-based sample. Methods The study adopted a cross-sectional design. Education level and financial status were used as measures of SES, while functional HL was assessed with the Newest Vital Sign. Moderated mediation analyses were conducted using SES variables as independent variables, SRH as dependent variable and functional HL as mediator variable. Furthermore, age, sex and chronic diseases were tested as moderators of the effect mediated by functional HL. Results 452 subjects completed the study (58,8% female; mean age 53,25 +/- 11,7). Results showed that functional HL mediates on average 18.5% of the association between education and SRH (p = 0.02) and 12.9% (p = 0.01) of the association between financial status and SRH. Furthermore, the proportion of effect mediated by functional HL was found to be higher in lower socio-economic classes for both SES variables considered. No significant moderation effects of age, sex or chronic diseases were observed for both SES variables. Conclusion Findings suggest that functional HL may serve as a pathway by which SES affects health status, especially in lower SES groups. HL may be a valuable and actionable intermediate target for addressing health inequalities. However, further studies are needed to better define the mediating role of HL across socio-economic classes.