Assessment of the quality of anticoagulation management with warfarin in a tertiary care center

OBJECTIVES: To evaluate the quality of an anticoagulation clinic in a tertiary hospital and identified factors affecting the time in the therapeutic range (TTR) and its relation to different complications. METHODS: This single-center retrospective study conducted between March 2015 and June 2016 included 1914 patients receiving warfarin therapy. They were divided into 4 warfarin indication groups: non-valvular atrial fibrillation (AF) (n=403), valvular AF (n=227), prosthetic valves (n=700), and venous or pulmonary embolism (n=584). RESULTS: The median age was 56 (25th, 75th percentiles: [45, 67]) years, and 53.2% were female. The median TTR was 0.52 (0.28, 0.76). Low hemoglobin (0.007) and high alkaline phosphatase (0.020) levels negatively affected the TTR. Venous thromboembolism (VTE) was associated with low TTRs. Minor bleeding occurred in 64 (3.35%), gastrointestinal bleeding in 14 (0.7%), and stroke in 41 (2.2%) patients, with no inter-group differences. The TTR was not associated with minor bleeding (odds ratio [OR]=0.49; p=0.09), gastrointestinal bleeding (OR=0.29; p=0.18), or stroke (OR=1.15; p=0.79). CONCLUSION: Reflecting the real-life experience of anticoagulation control, our patients spend less than half the TTR within the INR. The low target TTR mandates the need to improve service quality and control factors affecting the TTR, including hemoglobin levels and regular visits for patients with VTE.