Impact of health literacy and social support on medication adherence in patients with hypertension: a cross-sectional community-based study

BACKGROUND: Previous studies have examined the associations of health literacy and social support with medication adherence among patients with hypertension. However, limited evidence exists regarding the mechanisms underlying the relationship between these factors and medication adherence. PURPOSE: To explore the prevalence of medication adherence and its determinants in patients with hypertension in Shanghai. METHODS: A community-based cross-sectional study was conducted among 1697 participants with hypertension. We collected sociodemographic and clinical characteristics as well as data regarding health literacy, social support, and medication adherence using questionnaires. We examined interactions among the factors using a structural equation model. RESULTS: The participants included 654 (38.54%) patients with a low degree of medication adherence and 1043 (61.46%) patients with a medium/high degree of adherence. Social support directly influenced adherence (β = 0.165, P < 0.001) and indirectly influenced adherence through health literacy (β = 0.087, P < 0.001). Health literacy directly influenced adherence (β = 0.291, P < 0.001). Education indirectly affected adherence through both social support (β = 0.048, P < 0.001) and health literacy (β = 0.080, P < 0.001). Moreover, there was a sequential mediating effect of social support and health literacy on the association between education and adherence (β = 0.025, P < 0.001). After controlling for age and marital status, similar results were also obtained, indicating a good model fit. CONCLUSIONS: The degree of medication adherence among hypertensive patients needs to improve. Health literacy and social support had both direct and indirect effects on adherence, and thus, these factors should be considered as tools to improve adherence. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12872-023-03117-x.