Abstract TMP78: Healthcare Costs Before and After Stroke in Non-Valvular Atrial Fibrillation (NVAF) Patients Who Initiated Treatment With Rivaroxaban or Warfarin

Abstract

Objective: To compare total cost of care in pre- and post-stroke periods between rivaroxaban- and warfarin-treated NVAF patients. Methods: De-identified Optum Clinformatics® Database (OptumInsight, 2011-17) was used in this study of patients initiating rivaroxaban or warfarin within 30 days after a 1 st observed NVAF diagnosis. Patients had ≥6 months continuous health plan enrollment, CHA2DS2-VASc score ≥2 and no history of stroke or anticoagulation. Inpatient stroke diagnosis was identified by ICD-9/-10 code, and severity status was defined by National Institutes of Health Stroke Scale (NIHSS) score, imputed by a random forest method. For all patients who developed stroke, total per-patient per-month (PPPM) cost of care was estimated before (from treatment initiation to time of stroke) and after (from stroke until the earliest of either death or end of enrollment) stroke occurrence. Generalized linear models adjusted for confounders were used to compare PPPM cost between the 2 groups in the 2 periods, with gamma distribution, log link and weighted by follow up. Results: During a mean follow up of 27 months, 2.6% of rivaroxaban and 3.9% of warfarin patients developed stroke and were included in the analysis. During pre-stroke period, total cost of care was similar for both treatment groups (~$3400 PPPM), which increased 3-fold in the post-stroke period (Table 1). During post stroke period, total cost of care was 21% lower for rivaroxaban patients vs. warfarin. Of those with less severe stroke (NIHSS<16) total cost was 40% lower for rivaroxaban patients vs. warfarin. Conclusions: Total cost of care for stroke prevention was similar in rivaroxaban and warfarin treated patients, but post-stroke cost was lower in rivaroxaban patients. These findings suggest favorable long-term cost benefit with rivaroxaban, driven by significant savings in less severe stroke.