Geographical Variation in the Use of Oral Anticoagulation and Clinical Outcomes among Patients with Atrial Fibrillation in Denmark, Sweden, and Finland

Lars Frost; Olli Halminen; Mika Lehto; K E Juhani Airaksinen; Tomas Andersson; Per Wändell; Martin Holzmann; Pia Cordsen; Nicklas Vinter; Søren Paaske Johnsen

doi:10.1055/a-2080-6171

Geographical Variation in the Use of Oral Anticoagulation and Clinical Outcomes among Patients with Atrial Fibrillation in Denmark, Sweden, and Finland

TH Open. 2023 Jun 6;7(2):e133-e142. doi: 10.1055/a-2080-6171. eCollection 2023 Apr.

Authors

Lars Frost^{1

2}, Olli Halminen³, Mika Lehto^{4

5}, K E Juhani Airaksinen⁶, Tomas Andersson⁷, Per Wändell⁸, Martin Holzmann^{9

10}, Pia Cordsen¹¹, Nicklas Vinter^{1

2

11}, Søren Paaske Johnsen¹¹

Affiliations

¹ Diagnostic Centre, Silkeborg Regional Hospital, Silkeborg, Denmark.
² Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
³ Department of Industrial Engineering and Management, Aalto University, Espoo, Finland.
⁴ Department of Internal Medicine, Hospital District of Helsinki and Uusimaa, Lohja Hospital, Lohja, Finland.
⁵ Heart and Lung Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
⁶ Turku University Hospital, University of Turku, Turku, Finland.
⁷ Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
⁸ Division of Family Medicine and Primary Care, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden.
⁹ Functional Area of Emergency Medicine, Karolinska University Hospital, Stockholm, Sweden.
¹⁰ Department of Internal Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
¹¹ Danish Center for Clinical Health Services Research, Aalborg University, Aalborg, Denmark.

Abstract

Background Geographical mapping of variations in the treatment and outcomes of a disease is a valuable tool for identifying inequity. We examined international and intranational variations in initiating oral anticoagulation (OAC) therapy and clinical outcomes among patients with atrial fibrillation (AF) in Nordic countries. We also tracked real-world trends in initiating OAC and the clinical outcomes. Methods We conducted a registry-based multinational cohort study of OAC-naive patients with an incident hospital diagnosis of AF in Denmark ( N = 61,345), Sweden ( N = 124,120), and Finland ( N = 59,855) and a CHA ₂ DS ₂ -VASc score of ≥1 in men and ≥2 in women between 2012 and 2017. Initiation of OAC therapy was defined as dispensing at least one prescription between 90 days before and 90 days after the AF diagnosis. Clinical outcomes included ischemic stroke, intracerebral hemorrhage, intracranial bleeding, other major bleeding, and all-cause mortality. Results The proportion of patients initiating OAC therapy ranged from 67.7% (95% CI: 67.5-68.0) in Sweden to 69.6% (95% CI: 69.2-70.0) in Finland, with intranational variation. The 1-year risk of stroke varied from 1.9% (95% CI: 1.8-2.0) in Sweden and Finland to 2.3% (95% CI: 2.2-2.4) in Denmark, with intranational variation. The initiation of OAC therapy increased with a preference for direct oral anticoagulants over warfarin. The risk of ischemic stroke decreased with no increase in intracranial and intracerebral bleeding. Conclusion We documented inter- and intranational variation in initiating OAC therapy and clinical outcomes across Nordic countries. Adherence to structured care of patients with AF could reduce future variation.

Keywords: anticoagulation; atrial fibrillation; bleed; geographical variation; stroke.

The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. ( https://creativecommons.org/licenses/by/4.0/ ).

Grants and funding

Funding This work was supported by Bristol Myers Squibb and Pfizer through a grant from the ERISTA program. The ERISTA program had no influence on the conception of the study, writing of the protocol, data analyses, and interpretation or writing of the manuscript.