Predictors of Healthcare Costs After Initiating Dabigatran Versus Warfarin

Objectives: To identify patient characteristics predictive of all-cause healthcare costs among individuals with newly diagnosed non-valvular atrial fibrillation (NVAF) who initiated oral anticoagulant therapy with dabigatran or warfarin. Study Design: Retrospective analysis of administrative claims data of patients with newly diagnosed NVAF. Methods: Dabigatran and warfarin cohorts were identified by first claim (index date) during 10/1/2010 to 11/30/2012. Episode-based costs (all-cause) were determined using Episode Treatment Group (ETG) methodology and computed as per-patient-per-month. Baseline predictors of cost included baseline characteristics and baseline Episode Risk Group (ERG) risk score, which was grouped into 6 categories. To assess cohort differences in subgroups of patients, predictor variables representing the interaction of treatment cohort with patient characteristics were of primary interest. Cost ratios were then computed for subgroups of patients with different characteristics. Results: Cohorts included 4150 dabigatran- and 11,032 warfarin-treated patients. Compared with warfarin, dabigatran patients were younger (mean age: 67.3 vs. 72.5 years; P<0.001) and had lower mean ERG risk scores (4.1 vs. 5.6, P<0.001). Treatment cohort was not a statistically significant predictor of costs. Compared with warfarin, dabigatran was associated with higher cost at ERG risk scores of 2.1 to 4.0 and lower cost at scores of 6.1 to 8.0. Conclusions: Adding to existing evidence that treatment with dabigatran (vs warfarin) for NVAF would not incur higher all-cause healthcare costs, this study found that differences in all-cause healthcare costs did not follow a trend across subgroups of patients with NVAF based on different ERG risk score categories, favoring either therapy.