Healthcare resource utilization and costs of rivaroxaban versus warfarin among non-valvular atrial fibrillation (NVAF) patients with obesity in a US population.

Aim: To assess the real-world healthcare resource utilization (HRU) and costs of patients with non-valvular atrial fibrillation (NVAF) and obesity newly initiated on rivaroxaban or warfarin in the US.

Methods: This retrospective study used IQVIA PharMetrics Plus data (01/2010-09/2019) to evaluate patients (≥18 years) with NVAF and obesity (body mass index ≥30 kg/m) initiated on rivaroxaban or warfarin (on or after 01/2013). Inverse probability of treatment weighting (IPTW) was used to adjust for confounding between cohorts. HRU and costs were assessed post-treatment initiation. Weighted cohorts were compared using Poisson regression models and cost differences, with 95% confidence intervals (CIs) and values generated using non-parametric bootstrap procedures.

Results: After IPTW, 10,555 and 5,080 patients were initiated on rivaroxaban and warfarin, respectively (mean age: 59 years). At 12 months follow-up, the rivaroxaban cohort had lower all-cause HRU, including fewer hospitalizations (rate ratio [RR]: 0.80, 95% CI: 0.74, 0.87), emergency room visits (RR: 0.89, 95% CI: 0.83, 0.97), and outpatient visits (RR: 0.72, 95% CI: 0.69, 0.77; all  < .05). Medical costs were also reduced in the rivaroxaban cohort (mean difference: -$6,759, 95% CI: -$9,814, -$3,311) due to reduced hospitalization costs (mean difference: -$5,967, 95% CI: -$8,721, -$3,327), resulting in lower total all-cause healthcare costs compared to the warfarin cohort (mean difference: -$4,579, 95% CI: -$7,609, -$1,052; all  < .05). The rivaroxaban cohort also had lower NVAF-related HRU and medical costs driven by lower hospitalization at 12 months post-treatment initiation. HRU and cost reductions associated with rivaroxaban persisted up to 36 months of follow-up.

Limitations: Claims data may have contained inaccuracies and obesity was classified based on ICD diagnosis codes given that patient BMI values were not available.

Conclusions: Rivaroxaban was associated with reduced HRU and costs compared to warfarin among NVAF patients with obesity in a real-world US setting.