Knowledge, Adherence, and Satisfaction With Warfarin Therapy and Associated Factors Among Outpatients at University Teaching Hospital in Ethiopia

Abstract

Anticoagulation management using warfarin is challenging in clinical practice. This study aimed to evaluate the knowledge, adherence, and satisfaction with warfarin therapy and associated factors among outpatients at the Tikur Anbessa Specialized Hospital (TASH) in Addis Ababa, Ethiopia. An interview-based cross-sectional study was conducted among 350 patients receiving warfarin therapy at cardiac and hematology clinics of TASH. Anticoagulation knowledge assessment (AKA) questionnaires assessed the patients’ warfarin knowledge. Adherence to warfarin was evaluated using the Morisky Green Levine Scale (MGLS), and patient satisfaction with warfarin therapy was assessed using the 17-item anticlot treatment scale (ACTS). Binary logistic regression was used to determine factors associated with the outcome variables, and p < .05 was used as the cut-off point to declare a significant association. The mean AKA score was 59.35 ± 13.04% (10.68 ± 2.34 correct answers), and 82 (23.4%) of participants achieved a passing score. Based on the MGLS, 192 (54.9%) study participants adhered well to warfarin. The mean level of satisfaction was 53.67 ± 8.56, with mean scores of 41.93 ± 7.80 and 11.74 ± 2.43 in the ACTS burden and benefit subscales, respectively. One hundred eighty-four (52.6%) patients were satisfied with warfarin therapy. The absence of hyperthyroidism was significantly associated with poor knowledge of warfarin therapy (adjusted odds ratio [AOR] = 4.28, 95% confidence interval [CI]: 1.01–18.22). Those living with family had a 56% lower chance of poor warfarin adherence (AOR: 0.44; 95% CI: 0.21–0.93) than those living alone. This study shows room for improvement in patient knowledge, adherence, and satisfaction with warfarin therapy.