Factors Associated With Nonadherence to Cardiovascular Medications: A Cross-sectional Study

BACKGROUND: Cardiovascular medications have well-established benefits in the primary and secondary prevention of cardiovascular diseases. Unfortunately, adherence to these medicines is often suboptimal. To develop interventions intended to enhance adherence to cardiovascular medications, more insight is needed into the complex character of medication nonadherence. OBJECTIVE: The aim of the present study was to identify which factors are associated with nonadherence to cardiovascular medications in a sample of patients from Dutch community pharmacies. METHODS: In this cross-sectional study, patients using cardiovascular medications from 23 community pharmacies were included. Patient demographics, medication and disease characteristics, knowledge, quality of life, attitude toward medicines, and satisfaction with information were assessed. Both an adherent sample (n = 146) and a sample of patients nonadherent to prescribed medications (n = 109) during the last 6 months as assessed with pharmacy refill data (proportion of days covered <80%) were selected. Associations with refill nonadherence were assessed using univariate and multivariate logistic regression analyses. RESULTS: In total, 255 patients participated (53.3% men, 71.6 ± 10.9 years). Factors associated with cardiovascular medication nonadherence in multivariate analyses included experiencing difficulties with medication use due to forgetting, having insufficient knowledge on what to do when a dose is forgotten, and having an ambivalent attitude toward medicines (beliefs of high necessity and high concerns). CONCLUSIONS: Intervention strategies to enhance cardiovascular medication nonadherence should be targeted mainly to the unintentional dimension of nonadherence and include information and tools to prevent forgetting. Conversely, the influence of factors that underlie intentional nonadherence, particularly patients' beliefs about medicines, should also be addressed.