This study aims to evaluate the use of rivaroxaban and its short term safety when used by patients for the new indications of prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation, treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE) and prevention of recurrent DVT and PE. Any adult patient started by their care team on rivaroxaban or an alternative anticoagulant for the specified indications during the study period will be eligible to take part. A questionnaire will be completed by the care team of each patient at the start of treatment and again 12 weeks later. The care team will complete the questionnaires using information from the patient's medical notes, not by asking the patient directly. If a participant has an adverse event during the 12 week period, we may ask the patient's care team to fill out a further follow up questionnaire. No other examinations or tests will be performed. Patients will only be recruited to the study after the clinical decision to prescribe rivaroxaban or an alternative anticoagulant has been made, so that prescribing behaviour is not altered by the study. It is an observational, non-interventional study covering the whole of England and Wales.

Inclusion Criteria:

• age 18 years or above after study start
• index date on or after study start
• signed, informed consent
• patients treated for DVT or PE
• patients with non-valvular AF (with one or more risk factors) treated for prevention of stroke and systemic embolism

Exclusion Criteria:

• any use of univalent direct thrombin inhibitor or direct factor Xa inhibitors
• use of anticoagulant therapy or other vitamin K antagonists recorded within one year prior to index date

Patients prescribed rivaroxaban or an alternative anticoagulant in the secondary care hospital setting in England and Wales for the prevention of stroke in patients with AF, the treatment of DVT or PE, or the prevention of recurrent DVT and PE.