Aspirin does not improve survival for patients admitted to hospital with coronavirus, a study has found.
Patients with Covid-19 are at increased risk of blood clots forming in their blood vessels, particularly in the lungs.
Between November 2020 and March 2021, the Recovery trial included nearly 15,000 patients admitted to hospital with the virus an assessment of the effects of aspirin, which is widely used to reduce blood clotting in other diseases.
A total of 7,351 patients were randomised to receive 150 mg of aspirin once daily and compared with 7,541 patients randomised to usual care alone.
The study found no evidence that the drug treatment reduced mortality.
But the research did find that patients allocated to aspirin had a slightly shorter hospital stay, eight days versus nine days, and a higher proportion were discharged from hospital alive within 28 days (75% vs 74%).
For every 1000 patients treated with aspirin, approximately six more patients experienced a major bleeding event and approximately six fewer experienced a thromboembolic (clotting) event, researchers said.
Peter Horby, professor of emerging infectious diseases in the Nuffield Department of Medicine, University of Oxford, and joint chief investigator for the Recovery trial, said: “The data show that in patients hospitalised with Covid-19, aspirin was not associated with reductions in 28-day mortality or in the risk of progressing to invasive mechanical ventilation or death.
“Although aspirin was associated with a small increase in the likelihood of being discharged alive this does not seem to be sufficient to justify its widespread use for patients hospitalised with Covid-19.”
Martin Landray, professor of medicine and epidemiology at the Nuffield Department of Population Health, University of Oxford, and joint chief investigator, said: “There has been a strong suggestion that blood clotting may be responsible for deteriorating lung function and death in patients with severe Covid.
“Aspirin is inexpensive and widely used in other diseases to reduce the risk of blood clots so it is disappointing that it did not have a major impact for these patients.
“This is why large randomised trials are so important – to establish which treatments work and which do not.”
The Recovery trial was set up to test a range of potential treatments for patients admitted to hospital with Covid-19.