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Wolfson Institute of Preventive Medicine - Barts and The London

ORANGE study

Centre of Environmental and Preventive Medicine

Principal Investigator:  Dr Peter MacCallum,


  • Oral Anticoagulant Agent-associated Bleeding Events Reporting System (ORANGE)

The use of oral anticoagulants (OAC) in the prevention and treatment of arterial or venous thromboses significantly reduces morbidity and mortality. Yet one of the most devastating complications is the development of major bleeding, particularly intracranial haemorrhage. Unlike warfarin, the effects of the new OAC cannot be reversed; with their expanding uptake, we predict that these complications will increase in frequency and severity. The ORANGE study is a 3-year observational study collecting prospective anonymous data on current management practices and clinical outcomes of OAC-associated major bleeding events across the UK, in order that we may develop better management strategies for the future and provide a knowledge base for further research.


Main Contact

Dr Peter MacCallum
Phone: +44 (0) 20 7882 6203