Abstract WP344: Total Healthcare Costs Before and After Stroke in Non-Valvular Atrial Fibrillation (NVAF) Patients Who Initiated Treatment With Rivaroxaban or Warfarin

Abstract

Introduction: Healthcare expenditures remain unclear in NVAF patients initiating anticoagulation therapy. Objective: To compare total healthcare cost in pre- and post-stroke periods between rivaroxaban- and warfarin-treated NVAF patients. Methods: This retrospective study using de-identified IBM MarketScan Commercial and Medicare databases (2011-2019) included patients initiating rivaroxaban or warfarin within 30 days after a 1 st observed NVAF diagnosis who later developed ischemic or hemorrhage stroke. Patients had ≥6 months continuous health plan enrollment, CHA 2 DS 2 -VASc score ≥2 and no history of stroke or anticoagulation therapy. Inpatient stroke diagnosis was identified by ICD-9/-10 code, and stroke severity status was defined by National Institutes of Health Stroke Scale (NIHSS) score, imputed by a random forest method. Total per-patient per-year (PPPY) cost of care was calculated pre- and post-stroke (from treatment initiation to time of stroke and from stroke until end of study enrollment, respectively). Cost increases pre-/post-stroke were compared within each treatment cohort. Results: During a mean follow up of 25 and 30 months for rivaroxaban and warfarin respectively, 272 (2.0%) and 1,303 (3.3%) patients, respectively, developed stroke. For the rivaroxaban cohort, the pre-/post-stroke cost increase was lower than that for warfarin (1.79-fold vs 3.08-fold, respectively); for more severe stroke (NIHSS ≥6), the cost increase for rivaroxaban was half that of warfarin (3.19-fold increase vs 6.37-fold increase, respectively). Conclusions: The study showed a substantial increase in total cost of care following stroke, especially among patients with severe strokes. Warfarin patients had a much higher increase in post-stroke costs relative to rivaroxaban patients, suggesting a benefit of rivaroxaban in preventing strokes with poor outcomes that are costly.