Examining Adherence to Medication in Patients With Atrial Fibrillation

BACKGROUND/OBJECTIVES: This study examined whether beliefs about medicines, drug attitudes, and depression independently predicted anticoagulant and antiarrhythmic adherence (focusing on the implementation phase of nonadherence) in patients with atrial fibrillation (AF). METHODS: This cross-sectional study was part of a larger longitudinal study. Patients with AF (N = 118) completed the Patient Health Questionnaire-8. The Beliefs about Medicines Questionnaire, Drug Attitude Inventory, and Morisky-Green-Levine Medication Adherence Scale (self-report adherence measure), related to anticoagulants and antiarrhythmics, were also completed. Correlation and multiple logistic regression analyses were conducted. RESULTS: There were no significant differences in nonadherence to anticoagulants or antiarrhythmics. Greater concerns (r = 0.23, P = .01) were significantly, positively associated with anticoagulant nonadherence only. Depression and drug attitudes were not significantly associated with anticoagulant/antiarrhythmic adherence. Predictors reliably distinguished adherers and nonadherers to anticoagulant medication in the regression model, explaining 14% of the variance, but only concern beliefs (odds ratio, 1.20) made a significant independent contribution to prediction (χ = 11.40, P = .02, with df = 4). When entered independently into a regression model, concerns (odds ratio, 1.24) significantly explained 10.3% of the variance (χ = 7.97, P = .01, with df = 1). Regressions were not significant for antiarrhythmic medication (P = .30). CONCLUSIONS: Specifying medication type is important when examining nonadherence in chronic conditions. Concerns about anticoagulants, rather than depression, were significantly associated with nonadherence to anticoagulants but not antiarrhythmics. Anticoagulant concerns should be targeted at AF clinics, with an aim to reduce nonadherence and potentially modifiable adverse outcomes such as stroke.