Risk of major bleeds associated with the use of direct oral anticoagulants in venous thromboembolism

Date of Approval
Application Number
Technical Summary

The objective of this study is to assess the safety of DOACs for the treatment of VTE using real-world, population-based data sources to inform policy development and clinical practice. We will conduct a matched cohort study to assess the safety of DOACs compared with vitamin K antagonists (VKA) such as warfarin among patients with incident VTE. The investigators will carry out separate population based cohort studies using administrative health databases in Canada, the United States (US), and the United Kingdom (UK). VKA-users will be matched to DOAC-users based on age, sex, date of cohort entry and propensity score. To determine the adjusted hazard of study outcomes with DOACs use (compared with VKA), we will perform multivariable Cox proportional hazards regression to estimate the hazard ratios and their corresponding 95% confidence intervals. Analyses will be performed separately at each of the participating CNODES sites according to a common analytical protocol and then pooled using meta-analysis.

Health Outcomes to be Measured

Hospitalization or visit to the emergency department for a major bleed All-cause mortality


Samy Suissa - Chief Investigator - McGill University
Christel Renoux - Corresponding Applicant - McGill University
Brenda R Hemmelgarn - Collaborator - University of Calgary
Lisa Lix - Collaborator - University of Manitoba
Min Jun - Collaborator - University of Calgary
Pierre Ernst - Collaborator - McGill University
Sophie Dell'Aniello - Collaborator - McGill University


HES Accident and Emergency;HES Admitted Patient Care