Abstract
The RECOVERY trial is a large multi-armed, adaptive randomised controlled trial of treatments for Covid-19. It has rapidly recruited and demonstrated that hydroxychloroquine is ineffective in reducing mortality for hospitalised patients, whilst dexamethasone significantly reduces mortality among those patients using supplemental oxygen or on a ventilator. We estimate that the speed of recruitment and dissemination has probably decreased mortality in the UK by at least 200 hospitalised patients in the first month since the British Prime Minister announced the results. Despite its impressive speed, the trial only recruited about 10-15% of eligible patients, with recruitment rates ranging between 3% to 80% at participating hospitals. Had the trial recruited 50% of the eligible patients then our analysis suggests that more than 2,000 additional lives could have been saved. In a pandemic, rapid recruitment with high centre recruitment is absolutely essential to reduce deaths. Methods of improving site specific recruitment rates need investigating urgently.