Discovery of four COVID-19 risk groups helps guide treatment

People who are admitted to hospital with Covid-19 can be divided into four distinct groups, according to data from the world’s largest study of patients with the disease. Researchers identified the groups using clinical information and tests carried out upon arrival at hospital to predict the patients’ risk of death - ranging from low to very high.

A Covid-19 risk identification tool - the most accurate to date - has been designed using the groupings to help clinical staff choose the best course of treatment for patients admitted to hospital.

The tool was built by the ISARIC Coronavirus Clinical Characterisation Consortium involving researchers from Universities of Edinburgh, Glasgow, Liverpool and Imperial

College London using data from some 35,000 patients admitted to hospital between February and May 2020 who met the criteria for one of the four groups.

The tool was then tested and confirmed to be accurate using data from a further 22,000 patients hospitalised from the end of May to the end of June 2020.

Some of the data used to identify which group a person falls into - and, therefore, their risk of dying - included age, sex, the number of pre-existing conditions, respiratory rate on admission, and the results of two blood tests.

One in every hundred patients in the low-risk group was found to be at risk of dying. It was 10 in a hundred patients in the intermediate-risk group, 31 in a hundred in the high-risk group and 62 in a hundred in the very high-risk group.

The categorisations make new treatment pathways possible, researchers say.