Abstract 277: Comparison of All-Cause Hospitalization Rates and 30-Day Readmissions Among Patients With Non-Valvular Atrial Fibrillation, Newly Diagnosed and Newly Treated With Dabigatran, Rivaroxaban or Warfarin

Abstract

Background: While dabigatran has been evaluated in real-world studies compared to warfarin, this is one of the first head-to-head studies that includes a new oral anticoagulant in the comparison of all-cause hospitalization and 30-day readmission. Methods: Adult non-valvular atrial fibrillation (NVAF) patients newly diagnosed and newly treated with dabigatran, rivaroxaban or warfarin were identified within MarketScan claims databases between 10/01/2010-12/31/2014. Patients were continuously enrolled for 12-months prior to index date (first oral anticoagulant claim) and followed for 12 months or until medication switch, discontinuation, inpatient death or end of follow-up. Patients on dabigatran were matched 1:1 to patients on rivaroxaban and separately to patients on warfarin. High and low dose categorization of dabigatran and rivaroxaban were 150mg and 75mg BID and 15 mg and 20 mg QD, respectively. Incidence rate (IR, %) and 95% confidence intervals per 100 person-years for all-cause hospitalization were reported. Hazard ratios (HR) for all-cause hospitalization were estimated with Cox regression, adjusting for demographic and baseline clinical characteristics. Proportion of patients with all-cause 30-day readmission was compared. Results: A total of 26,592 and 33,046 dabigatran patients were matched to rivaroxaban and warfarin patients, respectively (mean age 68 years). Dabigatran patients had an IR for all-cause hospitalization of 41.3, (40.2-42.5) compared to rivaroxaban patients 42.5, (41.4-43.6) and an IR for all-cause hospitalization of 41.6, (40.7-42.6) compared with warfarin patients 45.0, (44.0-46.0). Among low and high dose prescriptions, patients on rivaroxaban and dabigatran had similar IRs of all-cause hospitalization (low dose: 53.8, (50.5-57.0) vs. 52.7, (48.9-56.5) and high dose: 39.1, (37.9-40.3) vs. 39.9. (38.8-41.1)). Cox regression results showed dabigatran patients compared to rivaroxaban patients had a significantly lower risk of all-cause hospitalization compared to warfarin (HR 0.96, p=0.05 and HR 0.93, p<0.001). Significantly fewer dabigatran patients were re-admitted 30-days post-discharge compared to warfarin [17.3% vs. 18.8% (4,201 out of 26,592 and 4,449 out of 26,592), p=0.04]. The proportion of patients with a 30-day readmission was comparable between dabigatran and rivaroxaban [17.2% vs. 18.5% (5,439 out of 33,046 and 5,623 out of 33,046), p=0.10]; however, time post-discharge to readmission was significantly longer for dabigatran patients (8.7 days vs 8.2 days, p=0.013). Conclusions: Adjusted results show dabigatran patients had significantly lower all-cause hospitalization compared to rivaroxaban and warfarin patients. Fewer dabigatran patients experienced a 30-day readmission post-discharge compared to warfarin patients and similar 30-day readmission post-discharge compared to rivaroxaban patients.