ABSTRACT
Background: In Italy, since the first symptomatic cases of Coronavirus disease 2019 (COVID-19) appeared in late February 2020, 205.463 cases of Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) were reported as of April 30, causing an high rate of hospital admission through the Emergency Department (ED).Objectives: The aim of the study was to evaluate the accuracy of ROX index in predicting hospitalization and mortality in patients with suspected diagnosis of COVID-19 in the ED. Secondary outcomes were to assess the number of readmissions and the variations of ROX index between first and second admission.Methods: This is an observational prospective monocentric study, conducted in the ED of Policlinico Sant’Orsola-Malpighi in Bologna. We enrolled 1371 consecutive patients with suspected COVID-19 and ROX index was calculated in 554 patients. Patients were followed until hospital discharge or death. Results: ROX index value < 25.7 was associated with hospitalization (AUC=0.737, 95%CI 0.696–0.779, p<0.001). ROX index < 22.3 is statistically related with higher 30-days mortality (AUC= 0.764, 95%CI 0.708-0.820, p<0.001). 8 patients were discharged and returned in the ED within the following 7 days, their mean ROX index was 30.3 (6.2; range 21.9-39.4) at the first assessment and 24.6 (5.5; 14.5-29.5) at the second assessment, (p=0.012).Conclusion: ROX index, together with laboratory, imaging and clinical findings, can help discriminate patients suspected for COVID-19 requiring hospital admission, their clinical severity and their mortality risk. Furthermore, it can be useful to better manage these patients in territorial healthcare services, especially in the hypothesis of another pandemic.