A key aim of risk stratification is to support clinical management decisions. Four risk classes were identified and showed similar adverse outcome rates across the validation cohort. Patients with a 4C Mortality Score falling within the low risk groups (mortality rate 1%) might be suitable for management in the community, while those within the intermediate risk group were at lower risk of mortality (mortality rate 10%; 22% of the cohort) and might be suitable for ward level monitoring. Similar mortality rates have been identified as an appropriate cut-off value in pneumonia risk stratification scores (CURB-65 and PSI).2122 Meanwhile patients with a score of 9 or higher were at high risk of death (around 40%), which could prompt aggressive treatment, including the initiation of steroids49 and early escalation to critical care if appropriate.