Prospective, multicenter, observational study with a three-year inclusion period (from January 1, 2012 to December 31, 2015) and a 6-month follow-up

All adults subjects living in the five well-defined areas affiliated to the French National Health Insurance System and having had at least one reimbursement of any antithrombotic in the 3-year study period are identified by using data from the National Health reimbursement database (Système National d'Information Inter-Régimes de l'Assurance Maladie, SNIIR-AM). SNIIR-AM contains individualized, anonymous and comprehensive data for all health spending reimbursements of affiliated subjects, including basic patient demographic data, medical drugs as well as outpatient medical care, prescribed or performed by health-care professionals from both public and private practices. This allows to calculate a denominator (number of person-years of anti-thrombotic drug exposure).

Crude incidence rates of major bleeding per 100 person-months are calculated in antithrombotic users, anticoagulants and others; stratification on a modified HAS-BLED score allows fair comparison between anti-thrombotic drug classes.

Inclusion Criteria:

• Patient with major bleeding event associated with antithrombotic drug
• Patient older than 18 years old
• Information on 1 and 6-month follow-up is given pending non-opposition letter

Exclusion Criteria:

• Patients with major bleeding events associated with antithrombotic during hospitalization
• Patients with intentional overdose with antithrombotic drugs
• Patients with multi-trauma
• Patients living outside the defined influence areas of the five participating cities

Patients with major bleeding events associated with antithrombotic