Geographical variation in persistence to oral anticoagulation therapy and clinical outcomes among patients with atrial fibrillation initiating therapy in Denmark, Sweden, Norway and Finland

Aim: To examine international and regional variations in persistence of oral anticoagulation (OAC) therapy and incidence of clinical outcomes and mortality, among patients with incident atrial fibrillation (AF) in the Nordic countries. Methods: We conducted a registry-based multinational cohort study of OAC-naïve patients diagnosed with AF that redeemed at least one prescription of OAC after AF in Denmark (N = 25 585), Sweden (N = 59 455), Norway (N = 40 046) and Finland (N = 22 415). Persistence was dispensing at least one prescription of OAC from Day 365 after the first prescription and 90 days forward. Results: Persistence was 73.6% (95% confidence interval 73.0–74.1) in Denmark, 71.1% (70.7–71.4) in Sweden, 89.3% (88.2–90.1) in Norway and 68.6% (68.0–69.3) in Finland. One-year risk of ischemic stroke varied between 2.0% (1.8–2.1) in Norway and 1.5% (1.4–1.6) in Sweden and 1.5% (1.3–1.6) in Finland. One-year risk of major bleeding other than intracranial bleeding varied between 2.1% (1.9–2.2) in Norway and 5.9% (5.6–6.2) in Denmark. One-year mortality risk varied between 9.3% (8.9–9.6) in Denmark and 4.2% (4.0–4.4) in Norway. Conclusion: In OAC-naïve patients with incident AF, persistence of OAC therapy and clinical outcomes vary across Denmark, Sweden, Norway and Finland. Initiation of real-time efforts are warranted to ensure uniform high-quality care across nations and regions.