ASCOT closes the Anticoagulation Treatment Domain

On Thursday, 7 April 2022, the ASCOT Trial Steering Committee (TSC), with support from the Anticoagulation Domain-Specific Working Group (DSWG), made the decision to close the Anticoagulation Treatment Domain. The Domain was officially switched off on the study database at 4:30pm AEST on Friday, 8 April 2022. At the time of this decision, there was a total of 1575 participants enrolled in the Anticoagulation Domain worldwide.

The rationale for this decision is due to the feasibility of continuing the domain. The incidence of patients meeting the primary outcome for ASCOT has been much lower than initially anticipated, meaning a much larger sample of participants is needed to reach meaningful outcomes. We are seeing a much slower recruitment rate with a highly vaccinated population and less severe variant, that is resulting in less people being admitted to hospital for COVID pneumonitis. This means the Anticoagulation Treatment Domain is unlikely to reach a sample size that would meet a statistical trigger in a timely manner.

Reaching this milestone would not have been possible without the joint effort of all ASCOT sites and collaborators. Recruiting nearly 1,600 participants since the first patient was randomised into the Anticoagulation Treatment Domain in February 2021, is evidence of their hard work and commitment to the study. We would also like to thank the members of the Anticoagulation DSWG, for providing their expertise and time toward developing this domain. 

We look forward to reporting the results and contributing a final analysis of the effect of anticoagulation treatment of varying dose for patients with COVID-19. We hope the results from this domain will also contribute to meta-analyses and be pooled with other international clinical trials examining the effects of anticoagulation treatment for patients with COVID-19.