Oral anticoagulation therapy (OAC) entails a high potential for adverse events and strict adherence is needed.Thus, medication review and identification of safety issues and knowledge gaps about OAC is critically important. The polymedication check (PMC) is a reimbursed intermediate medication review focusing on adherence and medication management for Swiss primary care. Investigators aime to assess the impact of the PMC extended with a semi-structured interview focusing on OAC.