Dabigatran versus rivaroxaban for the prevention of stroke and systemic embolism in atrial fibrillation in Canada

Abstract

Canadian patients with atrial fibrillation (AF) in whom anticoagulation is appropriate have two new choices for anticoagulation for prevention of stroke and systemic embolism – dabigatran etexilate (dabigatran) and rivaroxaban. Based on the RE-LY and ROCKET AF trial results, we investigated the cost-effectiveness of dabigatran (twice daily dosing of 150 mg or 110 mg based on patient age) versus rivaroxaban from a Canadian payer perspective. A formal indirect treatment comparison (ITC) of dabigatran versus rivaroxaban was performed, using dabigatran clinical event rates from RE-LY for the safety-on-treatment population, adjusted to the ROCKET AF population. A previously described Markov model was modified to simulate anticoagulation treatment using ITC results as inputs. Model outputs included total costs, event rates, and quality-adjusted life-years (QALYs). The ITC found when compared to rivaroxaban, dabigatran had a lower risk of intracranial haemorrhage (ICH) (relative risk [RR] = 0.38; 95% confidence interval [CI] 0.21 – 0.67) and stroke (RR = 0.62; 95%CI 0.45–0.87). Over a lifetime horizon, the model found dabigatran-treated patients experienced fewer ICHs (0.33 dabigatran vs. 0.71 rivaroxaban) and ischaemic strokes (3.40 vs. 3.96) per 100 patient-years, and accrued more QALYs (6.17 vs. 6.01). Dabigatran-treated patients had lower acute care and long-term follow-up costs per patient ($52,314 vs. $53,638) which more than offset differences in drug costs ($7,299 vs. $6,128). In probabilistic analysis, dabigatran had high probability of being the most cost-effective therapy at common thresholds of willingness-to-pay (93% at a $20,000/QALY threshold). This study found dabigatran is economically dominant versus rivaroxaban for prevention of stroke and systemic embolism among Canadian AF patients.