Direct oral anticoagulants (DOACs) have the advantage of being administered orally at a fixed dose without laboratory monitoring, in contrast to the frequent international normalized ratio measurements used to adjust for vitamin K antagonists dosing. Rivaroxaban, has a short half-life. The anticoagulation effect rapidly decreases if medication adherence is suboptimal. Objective The purpose of this quantitative study (called RIVA) is to longitudinally describe adherence to rivaroxaban (implementation and persistence) in patients with deep vein thrombosis (DVT). Setting The community pharmacy of the Center for Primary Care and Public Health (Unisanté), University of Lausanne, Switzerland in collaboration with the angiology division of the Lausanne University Hospital (CHUV). Methods This is an observational study.