Evidence has shown that COVID-19 infections can lead to an increased risk of blood clots. Unfortunately, these blood clots can lead to individuals being admitted to hospital, or, unfortunately in severe cases, death.

Treatment and study objective

Enoxaparin is a blood-thinning drug which has been used by doctors and nurses in hospitals for many years to prevent the thickening of blood which may lead to a clot. It is easier for doctors to prevent new blood clots from forming than treating existing blood clots.

There was an urgent need to find a safe and effective treatment to prevent worsening of the disease that may lead to hospital admission and/or death. The ETHIC (Early Thromboprophylaxis in COVID-19) study aimed to find out if giving enoxaparin in an early stage of the COVID-19 disease can prevent individuals being admitted to hospital and/or death.

Scale and how it will work

The study took place in approximately 8 to 10 countries, in approximately 30 to 50 centres. ​

Patients were allowed to take part if they have had a confirmed COVID-19 infection, are ≥ 55 years of age and have at least two of the following additional risk factors; age ≥ 70 years, body mass index > 25 kg/m2, chronic obstructive pulmonary disease, diabetes, cardiovascular disease, or corticosteroid use.

Half the patients in the study received the blood-thinning drug enoxaparin for three weeks, and half received no enoxaparin. Individuals were randomly allocated to one of these groups.

After 21 days, the number of patients in each group who were either admitted to hospital, or died, were compared. The number of patients in each group who developed a blood clot (venous thromboembolism) was also compared. Further comparisons were made at both 50 and 90 days after the beginning of the study.