Purpose: Oral anticoagugulants (OACs) effectively reduce the risk for ischemic stroke in patients with atrial fibrillation (AF), but undertreatment and poor persistence with treatment are important problems. NOACs now provide alternatives to warfarin. This study compares the persistence with presently available antithrombotic treatments in AF patients with a CHA2DS2VASc score ≥2.
Methods: All first claims of either warfarin (n = 9969), dabigatran (n = 2701), rivaroxaban (n = 2074), apixaban (n = 1352), or aspirin (n = 4540) from April 2011 until December 2014, in individuals with non-valvular AF and CHA2DS2VASc scores of 2-9, were identified in the administrative health data register (VAL) of the Stockholm region (2.1 million inhabitants). Prescription claims were analyzed with and without multivariate analysis in relation to age, sex, prescriber category, prior OAC treatment, number of drugs, and death.
Results: The overall persistence with any OAC was 88.2% (CI 87.5-88.9) at 1 year and 82.9% (CI 81.8-83.9) at 2 years. After 1 year, the crude persistence was 85.0% (CI 84.2-85.9) with warfarin, 85.9% (CI 81.8-90.1) with apixaban, 74.4% (CI 72.3-76.5) with dabigatran, and 77.4% (CI 74.6-80.2) with rivaroxaban. Multivariate analysis confirmed significantly higher persistence with warfarin and apixaban than with dabigatran or rivaroxaban. The adherence (proportion of days covered >80%) was above 90% for all NOACs; significantly higher with rivaroxaban compared to dabigatran (p < 0.001), but not compared to apixaban (p = 0.14).
Conclusions: After 2 years, the persistence with any anticoagulant treatment was high in patients with non-valvular AF. Our results indicate better persistence with warfarin and apixaban than with dabigatran or rivaroxaban in regular care.
Keywords: Adherence; Anticoagulant; Antithrombotic; Atrial fibrillation; NOAC; Persistence.