Academy of Managed Care Pharmacy (AMCP) 23rd Annual Meeting and Showcase

Minneapolis, MN; April 27-29, 2011

Quantifying the Cost of Warfarin-Related Bleeding Events in Patients with Atrial Fibrillation

Warfarin prophylaxis reduces the rates of primary and secondary stroke in patients with atrial fibrillation (AF), but increases the risk of hemorrhage. AF patients who experienced a bleeding event after starting warfarin therapy required more frequent and longer hospitalizations and logged more emergency department and outpatient visits, according to data presented at the AMCP meeting. The authors of the Cost of Warfarin-Associated Bleeding in Atrial Fibrillation poster said the increased expense associated with warfarin-triggered bleeding events should be considered when assessing the cost-effectiveness of newer anticoagulant therapies in patients with AF. Researchers used the MarketScan database to identify individuals enrolled in their health plan for >1 year who took warfarin for AF between 2003 and 2007 (N = 48,069). Of these, 2938 patients had claims for a major (3.8%) or minor (1.9%) gastrointestinal (GI) bleed or an intracranial hemorrhage (0.4%; ICH), an event associated with a high mortality risk. Older patients with comorbid conditions were most likely to experience a bleed (P <.01), and 95% of the population was aged >50 years.

Per-patient healthcare expenses for the year after initiating warfarin therapy reached $41,903 in the ICH cohort, $40,586 in the major GI bleed group, and $24,347 in the minor GI bleed cohort, whereas 12-month costs for individuals with no bleed totaled $24,129. Medical care related to the bleed accounted for 50.8% of total costs for ICH patients, versus 30.8% for major GI bleed and 2.6% for minor GI bleed sufferers. Compared with the no-bleed group, annual medical expenses were 61.6% higher in the ICH cohort, 48.7% higher in the major GI cohort, and 0.2% higher in the minor GI cohort (P <.001 for all). Increases were due mainly to more and longer all-cause hospitalizations; stays averaged 13.1 days for ICH patients, 12.88 for major GI patients, and 7.69 for minor GI patients versus 7.08 for no-bleed patients. Bleed patients also averaged more outpatient visits than no-bleed patients. Warfarin cuts the risk of stroke in AF patients by two-thirds, said the authors, with an absolute reduction per year of 2.7% for primary stroke and 8.4% for secondary stroke versus placebo. This benefit, however, must be weighed against the risk of bleeding events and their costs. The authors suggest newer agents for anticoagulation therapy could reduce healthcare costs and improve outcomes.

This study was supported by Daiichi Sankyo, Inc.