Over the 10-year period, 314 patients were admitted to hospital for bleeding.
Analysis showed the risk of bleeding, in particular, the risk of fatal or disabling bleeding, increased with age.
Researchers found that for patients under 65 taking daily aspirin, the annual rate of bleeds requiring hospital admission was about 1.5 per cent, compared with 3.5 per cent for patients aged 75 to 84, and 5 per cent for those aged 85 or over.
The annual rate of life-threatening or fatal bleeds was less than 0.5 per cent, for patients under 65, 1.5 per cent for those aged 75 to 84 and almost 2.5 per cent for patients aged 85 or over, The Guardian reported.
"In the over-75s the risk of a serious bleed is higher, but the key point is that this risk is substantially preventable by taking proton-pump inhibitors (PPIs) alongside aspirin," said Peter Rothwell, a professor at Oxford University in the UK.
"Since many of the deaths are preventable by taking PPIs, people over 75 should be prescribed a PPI along with their aspirin. Regardless of age, nobody should suddenly stop taking aspirin without speaking to their doctor," Rothwell said.