A Study to Learn About the Effects of Medicines That Help in Thinning the Blood in People With Atrial Fibrillation (AF) Between 2016 and 2020 in France

The purpose of this study is to look at how many patients with AF had strokes, major bleeding and death in both people who had and had not taken any oral anticoagulant. Atrial fibrillation (AF) is an irregular and often very rapid heart rhythm (arrhythmia) that can lead to blood clots in the heart. This increases the risk of stroke. Anticoagulants are medicines, also called blood thinners, which help prevent blood clots from forming or getting bigger. This study includes patient's data from the database who: * Had at least one hospital stay with AF * Are new users of OACs for AF treatment * Are 18 years and older when they were confirmed to have AF All the patient's data included in this study would have either received the OAC therapy or not. This study aims to look at any events of strokes, major bleeding and death. The data of patients will be collected from the French national health insurance claims database (SNDS). The planned study period is thought to be from 1st January 2016 till 31st December 2020