Abstract 244: Anticoagulant Options and Inpatient Costs for Patients with Non-Valvular Atrial Fibrillation

Abstract

Background: For decades, warfarin has been the primary oral anticoagulant prescribed for stroke prophylaxis in non-valvular atrial fibrillation (NVAF). With the recently introduced target specific oral anticoagulants (TSOAC), coagulation laboratory monitoring and the need to achieve and maintain the target international normalized ratio (INR) are no longer required. We hypothesized that use of a TSOAC may reduce hospitalization costs for patients with NVAF requiring stroke prophylaxis. Objective: To compare hospitalization costs between hospitalized NVAF patients using warfarin or rivaroxaban in a real-world setting. Methods: A retrospective claims analysis was conducted using the Premier Perspective Comparative Hospital Database from 11/2010 to 9/2012. Adult patients hospitalized for NVAF after November 2011 were included. The first hospitalization for NVAF was defined as the index hospitalization. Patients using rivaroxaban during hospitalization were matched with up to four warfarin users by propensity score analyses. Index hospitalization and all hospitalization (i.e., both index and readmissions occurring between November 2011 and September 2012) costs were compared between the cohorts using generalized estimating equations with gamma distribution, log link, and adjusting for the matched design. A sub-analysis was performed for patients who received their first oral anticoagulant treatment on day three or later of their hospital stay. Sensitivity analyses were also conducted on matched cohorts with a primary diagnosis of AF. Results: The characteristics of the matched cohorts (2,809 rivaroxaban and 11,085 warfarin users) were well balanced. The mean age of both cohorts was 71 years and 49% of patients were female. The average index hospitalization cost of the rivaroxaban cohort was $11,993 vs. $13,255 for the warfarin cohort, and the cost difference (CD; $1,284) was significant (P<.001). Similarly, the corresponding all hospitalization cost were $13,900 vs. $16,697 for the rivaroxaban and warfarin cohorts, respectively, also significantly lower (CD= $2,798) for the rivaroxaban cohort (P<.001). The subset of patients who first received oral anticoagulation on day three or after also incurred significantly lower costs with rivaroxaban compared to warfarin (index hospitalization: $15,703 vs. $20,042, CD= $4,350, P<.001; all hospitalization: $18,499 vs. $24,897, CD= $6,388, P<.001). In patients with a primary diagnosis of AF, the rivaroxaban cohort had significantly lower costs compared to the warfarin cohort (index hospitalization: $6,686 vs. $8,376, CD=$1,609; all hospitalization: $8,157 vs. $10,746, P<.001, CD=$2,612, P<.001). Conclusion: In propensity-matched cohorts of NVAF patients treated with warfarin or rivaroxaban, a TSOAC, our data demonstrated significant index and overall hospital cost reductions associated with the TSOAC strategy.