Trends in anticoagulation management across community-based practices in the United States: the Anticoagulation Consortium to Improve Outcomes Nationally (ACTION) study.

Randomized trials have demonstrated the effectiveness of warfarin in preventing thromboembolism. Translating the results of randomized trials into usual care is difficult, however, as trial patients are highly selected and closely monitored. The Anticoagulation Consortium to Improve Outcomes Nationally (ACTION) study is a prospective observational assessment of anticoagulation care in 98 office-based practices and 3 hospital-based clinics in the United States. Site enrollment began in August 2000 and ended in February 2002 with 6761 patients recruited. The goals of this large prospective cohort study are (1) to gather data on complication rates associated with warfarin therapy across a broad range of patient ages and indications; (2) document trends in anticoagulation management and treatment practices; and (3) establish quality benchmarks for anticoagulation control and frequency of monitoring. This report describes the methodology and preliminary results. Analysis is ongoing, and full results will be reported in the future.