Aspirin does not improve survival for patients hospitalised with COVID-19, latest results from the RECOVERY trial show.

The wide-ranging randomised trial studied the effect of aspirin in nearly 15,000 patients admitted to hospital between November 2020 and March 2021. Patients were randomised to aspirin 150 mg once daily or to usual care.

There was no evidence that aspirin treatment reduced mortality. There was no significant difference in the primary endpoint of 28-day mortality (17% aspirin vs. 17% usual care; rate ratio 0.96). Patients allocated to aspirin had a slightly shorter duration of hospitalisation (median 8 days vs. 9 days) and a higher proportion were discharged from hospital alive within 28 days (75% vs. 74%; rate ratio 1·06).

Among those not on invasive mechanical ventilation at baseline, there was no significant difference in the proportion who progressed to invasive mechanical ventilation or death (21% vs. 22%; risk ratio 0·96). For every 1000 patients treated with aspirin, approximately 6 more patients experienced a major bleeding event and approximately 6 fewer experienced a thromboembolic event.

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.”

The results will be published on medRxiv and have been submitted to a peer-reviewed medical journal.