Negative predictive value of the FebriDx host response point-of-care test in patients presenting to a single Australian emergency department with suspected COVID-19: an observational diagnostic accuracy study.

OBJECTIVES: To determine the negative predictive value (NPV) of the FebriDx point-of-care host response device in patients presenting with symptoms suggestive of COVID-19 infection in a mostly immunised Australian emergency department (ED) population during the late 2021 phase of the COVID-19 pandemic. DESIGN: Observational diagnostic accuracy study comparing FebriDx point-of-care test to SARS-CoV-2 PCR. SETTING: An ED in Melbourne, Australia, with 63 000 annual presentations in 2021. PARTICIPANTS: Patients aged 16 and over who met the Victorian Department of Health case definition for suspected COVID-19 infection PCR testing. Patients meeting any of the following criteria were excluded: <16 years of age; acute respiratory symptom(s) with onset>14 days prior to testing; current immunosuppressive or interferon therapy; live immunisation within the last 30 days; fever lasting>7 days; antibiotic or antiviral use in the preceding 14 days; experience of major trauma, major surgical intervention or severe burns within the last 30 days. PRIMARY AND SECONDARY OUTCOME MEASURES: COVID-19 PCR results (detected, not detected) and FebriDx results (bacterial positive, viral negative, viral positive). RESULTS: 94 participants were enrolled (female: 46; male: 48), 34% of participants (tested positive for COVID-19 according to PCR results, with a background incidence among all adult ED attenders of 2.5%. The sensitivity of FebriDx for detection of COVID-19 was 56% (95% CI 40% to 100%) and specificity was 92% (95% CI 84% to 100%). For the population tested, this resulted in an NPV of 80% (95% CI 71% to 100%) and a positive predictive value of 78% (95% CI 60% to 100%). CONCLUSIONS: In the context of a population with low COVID-19 infection rates, an evolved variant of COVID-19 and a very high community COVID-19 vaccination rate, FebriDx demonstrated reduced sensitivity and NPV relative to results from earlier international tests. These contextual factors should be considered during any attempt to generalise the current results. TRIAL REGISTRATION NUMBER: ACTRN12620001029987 (Australian Clinical Trials).

Outcomes for emergency department patients with suspected and confirmed COVID-19: An analysis of the Australian experience in 2020 (COVED-5).

OBJECTIVE: The aim of the present study was to describe the characteristics and outcomes of patients presenting to Australian EDs with suspected and confirmed COVID-19 during 2020, and to determine the predictors of in-hospital death for SARS-CoV-2 positive patients. METHODS: This analysis from the COVED Project presents data from 12 sites across four Australian states for the period from 1 April to 30 November 2020. All adult patients who met local criteria for suspected COVID-19 and underwent testing for SARS-CoV-2 in the ED were eligible for inclusion. Study outcomes were mechanical ventilation and in-hospital mortality. RESULTS: Among 24 405 eligible ED presentations over the whole study period, 423 tested positive for SARS-CoV-2. During the 'second wave' from 1 July to 30 September 2020, 26 (6%) of 406 SARS-CoV-2 patients received invasive mechanical ventilation, compared to 175 (2%) of the 9024 SARS-CoV-2 negative patients (odds ratio [OR] 3.5; 95% confidence interval [CI] 2.3-5.2, P < 0.001), and 41 (10%) SARS-CoV-2 positive patients died in hospital compared to 312 (3%) SARS-CoV-2 negative patients (OR 3.2; 95% CI 2.2-4.4, P = 0.001). For SARS-CoV-2 positive patients, the strongest independent predictors of hospital death were age (OR 1.1; 95% CI 1.1-1.1, P < 0.001), higher triage category (OR 3.5; 95% CI 1.3-9.4, P = 0.012), obesity (OR 4.2; 95% CI 1.2-14.3, P = 0.024) and receiving immunosuppressive treatment (OR 8.2; 95% CI 1.8-36.7, P = 0.006). CONCLUSIONS: ED patients who tested positive for SARS-CoV-2 had higher odds of mechanical ventilation and death in hospital. The strongest predictors of death were age, a higher triage category, obesity and receiving immunosuppressive treatment.