The mediating effect of family health on the relationship between health literacy and mental health: A national cross-sectional survey in China

Background: Mental health problems significantly affect people's well-being and result in a huge health burden. Health literacy and family health are critical to reducing people's mental health problems. However, limited studies have addressed their complex interaction. Thus, this study aims to elucidate the mediating effect of family health on the relationship between health literacy and mental health. Methods: A national cross-sectional study based on multistage random sampling was conducted from July 10 to Sep 15, 2021, in China. Information about the public's health literacy, family health, and the level of three common mental health problems (depression, anxiety, and stress) was collected. A structural equation model (SEM) was applied to explore the mediating effect of family health on the relationship between health literacy and mental health. Results: A total of 11,031 participants were investigated. Approximately 19.93 and 13.57% of participants experienced moderate or severe depressive and anxiety symptoms, respectively. The SEM showed that health literacy was directly associated with mental health, with higher health literacy resulting in lower levels of depression (coefficient: -0.018, p = .049), anxiety (coefficient: -0.040, p < .001), and stress (coefficient: -0.105, p < .001). In addition, family health played a significant mediating effect (p < .001) between health literacy and mental health, contributing to 47.5, 70.9, and 85.1% of the total effect of health literacy on personal stress, anxiety, and depression, respectively. Conclusions: This study revealed that the improvement of health literacy is directly and indirectly associated with less likelihood of people's mental health problems via family health. Thus, future mental health interventions should be integrated and targeted both at individual level and the family level.