Warfarin Adherence and Its Associated Factors among Patients with Atrial Fibrillation
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Abstract
Purpose: To identify level of warfarin adherence and investigate factors associated with warfarin adherence in Thai patients with atrial fibrillation.
Design: Correlational predictive study.
Methods: This study was conducted at a university hospital in Thailand. One-hundred twenty patients with non-valvular atrial fibrillation receiving warfarin were recruited. Data were collected using Thai versions of Anticoagulation Measurement of Treatment Adherence Scale, Medication Regimen Complexity Index, Health Literacy Scale, and Beliefs about Oral Anticoagulation Survey. Descriptive statistics, Spearman’s correlation, and multiple linear regression analysis were applied to analyze the data.
Main Findings: The findings indicated that all participants in this study had high warfarin adherence ( = 5.76, SD = .25). However, only 45.8% of them could maintain International Normalized Ratio (INR) within the therapeutic range. The complexity of a warfarin regimen, health literacy, perceived benefits and perceived barriers of taking warfarin jointly predicted 14% of the variance in warfarin adherence (R2 = .140, F(4,115) = 4.664, p = .002). Participants with lower perceived barriers had better warfarin adherence (β = -.285, p = .002).
Conclusion and recommendations: Although all participants in this study adhered to warfarin, they still had risks of INR instability. Health care providers should pay more attention to decreasing barriers of taking warfarin to enhance warfarin adherence and maintaining INR within the target range.
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