Switching of oral anticoagulants in atrial fibrillation: a cohort study using Australian general practice data

Abstract

ABSTRACT Background We assessed switching patterns of oral anticoagulants (OACs) in patients with atrial fibrillation (AF) in the period following widespread availability of the direct-acting oral anticoagulants (DOACs). Research design and methods A retrospective cohort study was conducted using NPS MedicineWise’s MedicineInsight dataset, collected from Australian general practices. Patients with AF who newly commenced an OAC between 1 January 2013 and 30 September 2017 were included. The switching rate was calculated within 12 months post-initiation. Switching rates between OACs were compared, and predictors of switching were identified. Results We included 15,020 patients who were recorded as having been commenced on warfarin or a DOAC. Overall, 5.7% of patients switched their OAC within 12 months. The switching rates from warfarin, apixaban, dabigatran and rivaroxaban were 9.4%, 2.6%, 8.9% and 4.0%, respectively. Compared to apixaban, commencement on warfarin, dabigatran or rivaroxaban was associated with a higher risk of switching to another OAC. Patients with an estimated glomerular filtration rate (eGFR) <30 mL/min were more likely to switch from DOACs to warfarin and less likely to switch from warfarin, compared to those with an eGFR >60 mL/min. Conclusion There was a low switching rate between OACs in Australian general practice patients with AF. A key determinant of switching appeared to be kidney disease.