Epidemiology and clinical features of emergency department patients with suspected COVID-19: Insights from Australia's 'second wave' (COVED-4).

O'Reilly, G M; Mitchell, R D; Mitra, B; Akhlaghi, H; Tran, V; Furyk, J; Buntine, P; Wong, A; Gangathimmaiah, V; Knott, J; Raos, M; Chatterton, E; Sevior, C; Parker, S; Baker, S; Loughman, A; Lowry, N; Freeman, D; Sri-Ganeshan, M; Chapman, Nicole; Siu, S; Noonan, M P; Smit, D; Cameron, P A

OBJECTIVE The aim of this study was to describe the epidemiology and clinical features of patients presenting to the emergency department (ED) with suspected and confirmed COVID-19 during Australia's 'second wave'. METHODS The COVID-19 Emergency Department (COVED) Project is an ongoing prospective cohort study in Australian EDs. This analysis presents data from twelve sites across four Australian states for the period from 1 July to 31 August 2020. All adult patients who met criteria for 'suspected COVID-19' and underwent testing for SARS-CoV-2 in the ED were eligible for inclusion. Study outcomes included a positive SARS-CoV-2 test result, mechanical ventilation and in-hospital mortality. RESULTS There were 106,136 presentations to the participating EDs and 12,055 (11.4%; 95% CI: 11.2-11.6) underwent testing for SARS-CoV-2. Of these, 255 (2%) patients returned a positive result. Among positive cases, 13 (5%) received mechanical ventilation during their hospital admission compared to 122 (2%) of the SARS-CoV-2 negative patients (OR 2.7; 95% CI: 1.5-4.9, p=0.001). Nineteen (7%) SARS-CoV-2 positive patients died in hospital compared to 212 (3%) of the SARS-CoV-2 negative patients (OR 2.3; 95% CI: 1.4-3.7, p=0.001). Strong clinical predictors of the SARS-CoV-2 test result included self-reported fever, sore throat, bilateral infiltrates on CXR, and absence of a leucocytosis on first ED blood tests (p<0.05). CONCLUSIONS In this prospective multi-site study during Australia's 'second wave', a substantial proportion of ED presentations required SARS-CoV-2 testing and isolation. Presence of SARS-CoV-2 on nasopharyngeal swab was associated with an increase in the odds of death and mechanical ventilation in hospital.