Factors influencing anticoagulation control of patients on warfarin therapy at Windhoek Central Hospital’s Warfarin Clinic

Background: Thrombotic diseases are a global challenge. Warfarin remains the anticoagulant of choice in low- and middle-income countries. In 2017, a study reported suboptimal anticoagulation control of 29.4%, compared to the target of ≥ 65%, in patients who attended the Windhoek Central Hospital's warfarin clinic. Objective: Factors contributing to the suboptimal anticoagulation control had to be explored. Methods: To achieve this, 72 patients from the interventional cohort at the clinic were interviewed. Results: The majority (39%) of respondents had dosage-related factors, followed by 21% with diet-related factors, 19% reported factors associated with social determinants of health, and the least (5.6%) due to drug interactions in patients with a co-diagnosis of tuberculosis. Conclusion: The study highlighted the need for improved healthcare system support, such as equipping non-physician health cadres (pharmacists and nurses) with the ability to prescribe warfarin therapy and roll out point-of-care testing for patients with limited access to primary healthcare settings, improving access to medication at the primary healthcare facilities, and patient education to improve warfarin therapy outcomes.