Rivaroxaban versus warfarin treatment among morbidly obese patients with venous thromboembolism: Comparative effectiveness, safety, and costs
© 2019 The Authors Introduction: Limited data exist on direct-acting oral anticoagulants in morbidly obese patients with venous thromboembolism (VTE). We compared clinical and health/economic outcomes with rivaroxaban versus warfarin for VTE treatment in morbidly obese patients. Materials and methods: This retrospective 1:1 propensity score matched cohort study analyzed data from 2 US claims databases. VTE patients initiating rivaroxaban or warfarin were identified who had diagnosis codes for morbid obesity (ICD-9:278.01,V85.4; ICD-10:E66.01,E66.2,Z68.4) 12 months pre- or 3 months post-initiation and followed ≥3 months. Intent-to-treat (ITT) and on-treatment (OT) analyses were conducted using conditional logistic regression and generalized linear models to compare recurrent VTE and major bleeding risks, healthcare resource utilization (HRU), and per patient per year (PPPY) costs. Results: In total, 2890 matched pairs of morbidly obese VTE patients initiating rivaroxaban or warfarin were identified. Risks of recurrent VTE (ITT: OR: 0.99; 95% CI: 0.85–1.14) and major bleeding (OT: OR: 0.75; 95% CI: 0.47–1.19) were similar for cohorts. Anti-Factor Xa laboratory measurement was performed on <1% of rivaroxaban cohort. Hospitalizations (OR: 0.86; 95% CI: 0.77–0.96) and outpatient visits (OR: 0.23; 95% CI: 0.10–0.56), were lower with rivaroxaban versus warfarin (ITT analysis). Average total medical costs PPPY were $2829 lower with rivaroxaban versus warfarin ($34,824 vs $37,653), mainly driven by hospitalization costs. Total healthcare costs (including pharmacy) were similar ($43,034 vs $44,565). Conclusions: Morbidly obese VTE patients receiving rivaroxaban had similar risks of recurrent VTE and major bleeding versus warfarin. Rivaroxaban treatment yielded significantly less HRU and total medical costs, with similar total healthcare costs between groups.