Oral anticoagulants (OACs) effectively reduce the risk of stroke in atrial fibrillation (AF). Three non-vitamin K antagonist OACs (NOACs) are introduced in regular care based on promising results compared with warfarin in randomized trials. This study compares outcomes with NOAC vs. warfarin treatment in OAC naïve AF patients in routine care, including primary care, in a large region with decentralized anticoagulant treatment.