A Study of Adverse Events and Suspected Adverse Drug Reactions in Patients Under Apixaban for Prevention of Stroke and Systemic Embolism With Non-Valvular Atrial Fibrillation and Venous Thromboembolic Events in Patients Who Have Undergone Elective Hip or Knee Replacement Surgery

Inclusion Criteria: * A signed and dated informed consent document indicating that the patient (or a legally acceptable representative) has been informed of all pertinent aspects of the study. * Patients (men and women) over 18 years old. * Patients who have received at least one dose of apixaban for prevention of stroke and systemic embolism with non-valvular atrial fibrillation with one or more of the following stroke risk factors: prior stoke or transient ischaemic attack; age \>75; hypertension; diabetes mellitus; symptomatic heart failure (NYHA class \>II); or for prevention of venous thromboembolic events (VTE) in adult patients who have undergone elective hip or knee replacement surgery. * Subjects who are willing and able to comply with all scheduled visits. Exclusion Criteria: * Patients who have received apixaban in a clinical trial. * Patients who received apixaban for another indication locally approved or have a contraindication according to the information to prescribe of the product in Mexico. * Hypersensitivity to the active substance or to any of the excipients. * Active clinically significant bleeding. * Hepatic disease associated with coagulopathy and clinically relevant bleeding risk. * Lesion or condition considered a significant risk factor for major bleeding. This may include current or recent gastrointestinal ulceration, presence of malignant neoplasms at high risk of bleeding, recent brain or spinal injury, recent brain, spinal or ophthalmic surgery, recent intracranial haemorrhage, known or suspected oesophageal varices, arteriovenous malformations, vascular aneurysms or major intraspinal or intracerebral vascular abnormalities. * Concomitant treatment with any other anticoagulant agent e.g. unfractionated heparin (UFH), low molecular weight heparins (enoxaparin, dalteparin, etc.), heparin derivatives (fondaparinux, etc.), and oral anticoagulants (warfarin, rivaroxaban, dabigatran, etc.) except under specific circumstances of switching anticoagulant therapy. Concomitant medication with Nonsteroidal anti-inflammatory drugs (NSAIDs ). * Pregnancy and breast-feeding. * Severe acute or chronic psychiatric condition and other significant medical condition.