The relationship between health literacy and health outcomes among male young adults: exploring confounding effects using decomposition analysis

Objectives Previous studies indicate substantial correlations between low health literacy and poor health outcomes. However, empirical findings remain inconsistent and are theoretically challenging. In this study, we conceptually place health literacy within an established model of health inequality. Studying multiple pathways, we estimate the associations between health literacy and six health outcomes and decompose these associations with health literacy's covariates. Methods Cross-sectional data from the Young Adult Survey Switzerland was used for the analyses (n = 5959, age = 18-25). Logistic regression and KHB decomposition analyses were applied to estimate health literacy's coefficients and confounding percentages. Results Eleven covariates were associated with health literacy (p < 0.001). Ten covariates reduced the naive health literacy coefficient when included in the regression models (confounding percentages: 36.7-86.9%). In three out of six models, the confounding effects led to non-significant health literacy coefficients. Conclusions We found that health literacy's associations with health outcomes are confounded by socioeconomic, material, psychosocial, and health-related factors. More investigations on the causal importance of health literacy, respectively, on its potential to health promotion are required.