Tool predicts mortality in disease cases

Classification system will help medics make swift decisions over patient care

Researchers in the United Kingdom have designed a risk identification tool that predicts mortality in COVID-19 patients and could help doctors around the world make quick decisions regarding treatment plans.

The tool uses eight variables at initial hospital assessment to rank patients into four categories; low, intermediate, high or very high risk of mortality. These variables include: age, sex, number of comorbidities, respiratory rate, oxygen saturation, level of consciousness, urea level, and C reactive protein, which is an indicator of inflammation in the body.

The categorizations mean doctors can swiftly and efficiently decide on the best treatment for newly-admitted patients. For example, low-risk patients could carry out the rest of their treatment at home, whereas those who fall in the very high risk group might immediately qualify for aggressive treatment, such as the use of antivirals and early admission to critical care.

The tool was designed by ISARIC 4C, which is the UK-based novel coronavirus branch of the International Severe Acute Respiratory and Emerging Infection Consortium.

"As doctors, we want to identify groups of patients most at risk of dying from COVID-19," said Ewen Harrison, who is senior author on the research and professor of surgery and data science at the University of Edinburgh. "If we can do that at the front door of the hospital, then treatment can be better planned. This easy-to-use tool will help doctors make decisions to provide patients with the optimal care."

The tool is available online for use by clinicians, who can input levels ascertained from initial hospital assessment, and the system immediately returns a risk prediction known as the 4C Mortality Score.

Doctors and scientists based in more than a dozen UK cities contributed to the research, collecting data from more than 57,000 COVID-19 patients at 260 hospitals in England, Scotland and Wales between February and June this year.

One in every 100 patients in the low-risk group was found to be at risk of dying, according to research published by the consortium in the British Medical Journal. This rose to 10 out of 100 patients in the intermediate-risk group, 31 out of 100 in the high-risk group and 62 out of 100 in the very high-risk group.

Calum Semple, chief investigator for ISARIC 4C and professor in outbreak medicine at the University of Liverpool, said the tool will help medical professionals gear up for a potential rise in COVID-19 cases in the coming months. The UK government has already announced it will tighten lockdown measures from next Monday in order to prevent a renewed surge of infections.

"This winter is likely to see great pressures on our health services, with staff being redeployed to less familiar acute care areas," said Semple. "In these difficult circumstances, the 4C mortality score is likely to be a valuable tool for supporting decisions that allow prompt escalation of care to those most likely to benefit."