Efficacy and safety of warfarin management in US anticoagulation clinic

Excerpt

Introduction Previous studies from US have reported efficacy and safety outcomes of individual anticoagulation clinics (ACC) in the US but collective data has not been reported so far. The objective of this study was to assess efficacy and safety of warfarin therapy in US ACC. Methods Data was collected by postal survey in January 2006. The response rate was 27.9% (146 of 524 clinics); responses were based on 128,711 patients seen in last 1 year. The respondents were asked to report proportions for each question in the survey and the total number of patients seen in the clinic in the last 1 year. Data was analyzed by pooling the relevant number of patients for each question and adjusting the denominator on the basis of usable data. Results The majority of respondents were pharmacists (61%, 89 of 146) affiliated with hospitals (62.3%, 91 of 146). Atrial fibrillation and venous thromboembolisms were the two most common indications for anticoagulation therapy. The % of pts having difficulty in attaining therapeutic international normalized ratio (INR) in the first 4–6 weeks of therapy was 13.3 (14,135 of 106,335) and % of pts whose INR was poorly controlled (in range <50% of time) was 18.7 (19,831 of 106,216). The % of pts with INR controlled within therapeutic and expanded therapeutic range was 64% (74,787 of 117,075) and 76% (75,734 of 99,603), respectively. The % of pts who visited the emergency room (ER) and those who were hospitalized due to warfarin related adverse drug event was 3.1% (3,420 of 111,287) and 2.3% (2,561 of 113,104) respectively. Warfarin associated adverse drug event fatality rate was 0.2% (250 of 113,733). The % of pts who develop a thromboembolic event (TE), major and minor bleeding at least once during therapy with warfarin was reported to be 2.2 (2,492 of 110,916), 2.1 (2,352 of 109,756) and 16.2% (16,616 of 102,848), respectively. Conclusions This is the first study to report aggregate data on efficacy, safety and monitoring outcomes associated with warfarin therapy in US ACC. …