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

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).

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.

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.

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.