A clinical study circulated by the British Medical Journal (BMJ) claims strong evidence that prompt preventive blood-thinning drugs may reduce the risk of death in Covid-19 patients. Patients given preventive blood-thinning drugs (prophylactic anticoagulants) within 24 hours of admission to hospital with Covid-19 are less likely to die compared with those who do not receive them, a new study finds. Patients given preventive blood-thinning drugs (prophylactic anticoagulants) within 24 hours of admission to hospital with covid-19 are less likely to die compared with those who do not receive them. Clinical trials are now underway to see if prophylactic anticoagulants could be an effective treatment for Covid-19. In the meantime, the researchers say these findings provide strong real-world evidence to support their early use among patients in hospitals with Covid-19. Some Covid deaths are believed to be due to blood clots developing in major veins and arteries. Anticoagulants prevent blood clots from forming and have antiviral and potent anti-inflammatory properties, so might be particularly effective in patients with COVID-19, but results from previous studies have been inconclusive. To explore this further, a team of UK and US researchers set out to estimate the effect of prophylactic anticoagulants when given promptly after admission to hospital on the risk of death and severe bleeding among patients with Covid-19. Their findings are based on data from the United States Department of Veterans Affairs for 4,297 patients (average age 68 years; 93% men) admitted to hospital with covid-19 between 1 March and 31 July 2020.