Hospital patients with UK’s most common blood group – twice as likely to bleed to death, study finds

Having the most common blood group, O, makes you more than twice as likely to bleed to death from serious injuries, a study has found.

The blood group is associated with lower levels of a clotting agent which may result in greater bleeding, researchers believe. Forty-seven per cent of the UK population are type O.

Data from 901 emergency care patients in Japan showed a death rate of 28 per cent for those with type O blood. The death rate of patients from other blood groups combined was 11 per cent.

Lead researcher Dr Wataru Takayama, from Tokyo Medical and Dental University Hospital, said: ‘Loss of blood is the leading cause of death in patients with severe trauma. We wanted to test the hypothesis that trauma survival is affected by differences in blood types.’

Blood type is determined by proteins on the surfaces of red blood cells. The other main blood group categories are A, B and AB. Type O blood can generally be donated to anyone with no ill-effects. However, people with type O blood have lower levels of Von Willebrand factor, a blood clotting agent that may help prevent life-threatening bleeding.

More than forty-seven per cent of the UK population are type O – but this blood group makes you most likely to bleed to death, a study has found

Dr Takayama said the results, reported in the journal Critical Care, raised questions about the emergency transfusion of type O red blood cells to patients.

But having type O blood may have a positive side. Previous research suggests patients with that group may be less likely to suffer from blood clots.