For a study, researchers sought to compare the outcomes of hospitalization for recurrent VTE, major bleeding, and death after receiving prescriptions for apixaban, rivaroxaban, or warfarin following an initial 90 days of anticoagulation therapy. The exploratory retrospective cohort analysis included 64,642 persons who started oral anticoagulation after being discharged from the hospital for VTE and continued therapy beyond 90 days, using data from fee-for-service Medicare (2009-2017) and two commercial health insurance (2004-2018) databases. Apixaban, rivaroxaban, or warfarin may be administered following a 90-day course of VTE therapy. Hospitalization for recurrent VTE and severe hemorrhage were the primary outcomes. Propensity score weighting was used to correct the analyses. Patients were tracked from the conclusion of their initial 90-day therapy episode until treatment discontinuation, outcome, death, disenrollment, or the end of accessible data. The hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using weighted Cox proportional hazards models.
The study comprised 9,167 apixaban patients (mean [SD] age, 71  years; 5491 [59.9%] women), 12,468 rivaroxaban patients (mean [SD] age, 69  years; 7,067 [56.7%] women), and 43,007 warfarin patients (mean [SD] age, 70  years; 25,404 [59.1%] women). For recurrent VTE, the median (IQR) follow-up was 109 (59-228) days, and for significant bleeding, the median (IQR) follow-up was 108 (58-226) days. The incidence rate of hospitalization for recurrent VTE was significantly lower for apixaban compared to warfarin (9.8 vs 13.5 per 1,000 person-years; HR, 0.69 [95% CI, 0.49-0.99]), but not significantly different between apixaban and rivaroxaban (9.8 vs 11.6 per 1,000 person-years; HR, 0.80 [95% CI, 0.53-1.19]) or rivarox (HR, 0.87 [95% CI, 0.65-1.16]). Hospitalization rates for major bleeding were 44.4 per 1,000 person-years for apixaban, 50.0 per 1000 person-years for rivaroxaban, and 47.1 per 1,000 person-years for warfarin, resulting in HRs of 0.92 (95% CI, 0.78-1.09) for apixaban vs warfarin, 0.86 (95% CI, 0.71-1.04) for apixaban vs rivaroxaban, and 1.07 (95% CI, 0.93-1.24) for rivaroxaban vs warfarin.
Prescription dispenses for apixaban beyond 90 days, compared to warfarin beyond 90 days, were significantly associated with a modestly lower rate of hospitalization for recurrent VTE, but no significant difference in the rate of hospitalization for major bleeding, according to this exploratory analysis of patients prescribed extended-duration oral anticoagulation therapy after hospitalization for VTE. There were no statistically significant differences between apixaban and rivaroxaban or between rivaroxaban and warfarin.