Diagnostic accuracy of the molecular SARS-CoV-2 rapid test and its use in triaging hospital admissions in the emergency room

Background: A false-negative rapid antigen test of COVID-19 in healthcare settings not only causes delays in diagnosis, isolation and treatment but also leads to failures in the infection prevention and control practices of the hospital. Objectives: The study objective was to assess the diagnostic performance of ID NOW (Rapid polymerase chain reaction [PCR]) as a COVID-19 triage tool for medical admissions from the emergency room (ER) of our medium-sized tertiary hospital. Methodology: Molecular laboratory data with valid ID NOW and reverse transcription-PCR (RT-PCR) real time results were collected from February to September 2022 of patients presenting with symptoms of influenza-like illness and severe acute respiratory infections at ER. The diagnostic accuracy of ID NOW (sensitivity, specificity, positive predictive value and negative predictive value) was calculated against the laboratory's reference standard RT-PCR test. Results: A total of 153 patients were tested both by ID NOW and RT-PCR. The sensitivity and specificity of the ID NOW assay were 96% (95% confidence interval [CI] 92.49% to 98.92%) and 96.7% (95% CI 91.71% to 98.56%), respectively. Conclusion: ID NOW provided a rapid and reliable adjunct for the safe triage of patients with COVID-19 at our centre and can work effectively when integrated into a COVID-19 triage algorithm of the hospital. Diagnostic stewardship can pave the way for better infection control practices of hospitals.