Intentional and Unintentional Medication Non-Adherence in Hypertension: The Role of Health Literacy, Empowerment and Medication Beliefs.

Background: Medication non-adherence is a major public health issue, creating obstacles to effective treatment of hypertension. Examining the underlying factors of deliberate and non-deliberate non-adherence is crucial to address this problem. Thus, the goal of the present study is to assess the socio-demographic, clinical and psychological determinants of intentional and unintentional non-adherence. Design and methods: A cross-sectional survey was conducted between March, 2015 and April, 2016. The sample consisted of hypertension patients holding at least one medical prescription (N=109). Measurements assessed patients' medication adherence, health literacy, empowerment, self-efficacy, medication beliefs, and patients' acceptance of their doctor's advice, socio-demographic and clinical characteristics. Results: Patients who occasionally engaged in either intentional or unintentional non-adherence reported to have lower adherence self-efficacy, higher medication concern beliefs, lower meaningfulness scores and were less likely to accept the doctor's treatment recommendations. Patients who occasionally engaged in unintentional non-adherence were younger and had experienced more side effects compared to completely adherent patients. Adherence self-efficacy was a mediator of the effect of health literacy on patients' medication adherence and acceptance of the doctor's advice was a covariate. Conclusions: Regarding the research implications, health literacy and adherence self-efficacy should be assessed simultaneously when investigating the factors of non-adherence. Regarding the practical implications, adherence could be increased if physicians i) double-check whether their patients accept the treatment advice given and ii) if they address patients' concerns about medications. These steps could be especially important for patients characterized with lower self-efficacy, as they are more likely to engage in occasional non-adherence.