IntroductionIn May 2020 a virtual ward for COVID-19 patients seen at University College London Hospital (UCLH) was established. The aim of this study was to see if specific factors can be used to predict the risk of deterioration and need for Emergency Department (ED) reattendance or admission.MethodsWe performed a service evaluation of the COVID-19 virtual ward service at UCLH between 24/10/2020 and 12/2/2021. 649 patients were included with data collected on vital signs, basic measurements, and blood tests from their initial ED attendance, allowing calculation of ISARIC-4C mortality scores. Outcomes of interest were ED reattendance, facilitation of this by virtual ward physician, level of care if admitted, and death within 28 days of the first COVID-19 virtual ward appointment. Analysis was performed using Mann-Whitney U tests.ResultsReattendance rate to ED was 17.3% (112/649) of which 8% (51/649) were admitted. Half of ED reattendances were facilitated by the virtual ward service. Overall mortality was 0.92%. Patients who reattended ED, facilitated by the virtual ward service, had a higher mean CRP (53.63 vs 41.67 mg/L), presented to ED initially later in their COVID-19 illness (8 vs 6.5 days) and had a higher admission rate (61 vs 39%). The mean ISARIC-4C score was higher in the reattendance group compared to the non-reattendance group (3.87 vs 3.48, difference of 0.179, p = 0.003). The mean ISARIC-4C score was higher in the admission group than the non-reattendance group (5.56 vs 3.48, difference of 0.115, p = 0.003).ConclusionIdentification of patient risk factors for reattendance following a diagnosis of COVID-19 in ED can be used to design a service to safely manage patients remotely. We found that the ISARIC -4C mortality score was associated with risk of hospital admission and could be used to identify those requiring more active remote follow up.