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

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.

KEYWORDS:

• Atrial fibrillation
• Australia
• determinants
• DOACs
• general practice
• switching
• warfarin

Acknowledgments

We are grateful to the general practices that participated in the MedicineInsight program. We are also thankful for patients who permit the use of their de-identified data for MedicineInsight. The abstract of this study was presented at the International Society on Thrombosis and Haemostasis Congress, 17-19 July 2021and the Australasian Pharmaceutical Science Association Conference, 6-8 December 2021.

Author contributions

All authors substantially contributed to the conception, design, and interpretation of the study and revised it for its intellectual content. AT Kefale designed the study, interpreted findings, and drafted the writing and revised the manuscript. AT Kefale and WM Bezabhe performed the data analysis. GM Peterson, WM Bezabhe and LR Bereznicki participated in the design and concept of the study and critically revised the manuscript. All authors approved the final version for publication and agreed to take responsibility for the contents of the article.

Conflict of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants, or patents received or pending, or royalties

Data availability

Data sharing is restricted by the owner of the dataset; thus, data other than included in the manuscript will not publicly available.

Ethical approval

Ethics approval was obtained from the MedicineInsight Independent Data Governance Committee (2018-033) and the Human Research Ethics Committee of the University of Tasmania (H0017648). No written consent from the participants was needed as per the requirement of ethics approval for de-identified electronic health records.

Reviewer disclosures

A reviewer on this manuscript has disclosed being on the advisory board and providing consultancy for Bayer Switzerland AG (manufacturer of rivaroxaban). Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

This paper was not funded