New online tool ‘can identify Covid patients at highest risk of deterioration’ An online tool can identify Covid-19 patients who are at highest risk of deterioration (Peter Byrne/PA) An online tool that can identify Covid-19 patients who are at highest risk of deterioration is being made freely available to NHS doctors from Friday. The new risk-stratification tool, developed by researchers from the UK Coronavirus Clinical Characterisation Consortium (known as ISARIC4C), assesses data collected from hospital patients along with some standard laboratory tests. It then calculates a percentage risk of deterioration based on the information, which is known as the 4C Deterioration Score.