Abstract
Social support is necessary for patients with heart failure (HF) to take medication, which can lead to decreased hospitalization and mortality rates. However, the effect of patient health literacy on this relationship remains unclear. This study aimed to evaluate the mediating effect of health literacy on the relationship between social support and medication adherence among patients with HF. A cross-sectional correlational design was used between August and October 2024 for 249 patients with HF. Data were collected using patients' sociodemographic and health status, the Arabic version of the General Medication Adherence Scale (GMAS), BRIEF Health Literacy Screening Tool, and Oslo Social Support Scale (OSSS-3). Hayes' Process Macro program, version 4.2, Model 4, was used to assess the possible interaction effects. Statistical significance was set at p less than .05. There was a weak positive correlation between patients' medication adherence and health literacy (r = .247, p < .001) and social support (r = .204, p < .001). In addition, there was a significant correlation between HL status and social support (r = .314, p < .001). Factors that increased medication adherence included older age (B = 0.06, p = .027), not smoking (B = 2.21, p < .001), other chronic diseases (B = 1.23, p = .005), higher health literacy (B = 0.30, p = .002), and social support (B = 0.33, p = .044). The model indicated an indirect positive effect of social support on medication adherence through health literacy (β = 0.064, p = .007). Social support had a positive direct effect on health literacy (β = 0.314, p < .001) and a positive effect of health literacy on medication adherence (β = 0.203, p = .002). Social support had a significant positive direct effect on medication adherence (β = 0.140, p = .031), with a total effect of β = 0.204, p = .001. Health literacy showed a statistically significant indirect association in the mediation model. This study revealed that patients with higher health literacy are better equipped to manage complex treatment regimens and engage in self-care. This effect was further amplified by social support, which both directly and indirectly enhanced adherence.