Quality of Life and Efficacy Evaluation of Patient Self-monitoring Their Oral Anticoagulation Therapy

Inclusion Criteria: * Patient aged 18 years and over followed at the Montreal Heart Institute's Anticoagulation clinic * Warfarin treatment planned for at least 4 months after inclusion in the study * Warfarin treatment initiated for at least 6 months * Last 2 INRs between 1.5 and 4 if target INR is between 2 and 3 * Last 2 INRS between 2 and 4 if target INR is between 2.5 and 3.5 * Provide a signed informed consent Exclusion Criteria: * Patient unable to understand (spoken and written) French or English * Patient refuses or is unable to attend the required training sessions * Targeted INR other than 2 to 3 or 2.5 to 3.5 * Handicap or physical limitation compromising the patient's ability to initiate self-monitoring in the absence of a proxy helper * Moderate to severe cognitive impairment or important comprehension problems * Active neoplasm * Concurrent chemotherapy * Hypercoagulable conditions * Life expectancy of less than 1 year documented in the medical chart * Inclusion (at time of inclusion or 30 days prior to inclusion) in another research project involving a drug * Patient anticoagulated with nicoumalone * Pregnancy or breastfeeding * Active bleeding (except for menses) * Recent major bleeding (less than 3 months before inclusion) * Stroke, acute coronary syndrome, percutaneous coronary intervention, coronary artery bypass graft, cardiac valve replacement, deep veinous thrombosis or pulmonary embolism in the 3 months prior to inclusion * Any other condition that, in the opinion of the investigators, of the treating physician or of the healthcare professionals working at the anticoagulation clinic could make self-management by the patient impossible