Major bleeding was defined as the occurrence of any of the following: intracranial haemorrhage, retroperitoneal haemorrhage, blood loss leading to a transfusion of at least two units of whole blood or packed red blood cells, or bleeding resulting in a haemoglobin drop of more than 3 g/ dl, or a fall in haemoglobin greater than 4 g/ dl (or 12% of haematocrit) with no bleeding site identified.