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Utility of COVID-19 antigen testing in the emergency department.

Authors :: Peacock WF
Soto-Ruiz KM
House SL
Cannon CM
Headden G
Tiffany B
Motov S
Merchant-Borna K
Chang AM
Pearson C
Patterson BW
Jones AE
Miller J
Varon J
Bastani A
Clark C
Rafique Z
Kea B
Eppensteiner J
Williams JM
Mahler SA
Driver BE
Hendry P
Quackenbush E
Robinson D
Schrock JW
D'Etienne JP
Hogan CJ
Osborne A
Riviello R
Young S
Source :: Journal of the American College of Emergency Physicians open [J Am Coll Emerg Physicians Open] 2022 Jan 15; Vol. 3 (1), pp. e12605. Date of Electronic Publication: 2022 Jan 15 (Print Publication: 2022).
Publication Year :: 2022
Abstract: Background: The BinaxNOW coronavirus disease 2019 (COVID-19) Ag Card test (Abbott Diagnostics Scarborough, Inc.) is a lateral flow immunochromatographic point-of-care test for the qualitative detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein antigen. It provides results from nasal swabs in 15 minutes. Our purpose was to determine its sensitivity and specificity for a COVID-19 diagnosis. Methods: Eligible patients had symptoms of COVID-19 or suspected exposure. After consent, 2 nasal swabs were collected; 1 was tested using the Abbott RealTime SARS-CoV-2 (ie, the gold standard polymerase chain reaction test) and the second run on the BinaxNOW point of care platform by emergency department staff. Results: From July 20 to October 28, 2020, 767 patients were enrolled, of which 735 had evaluable samples. Their mean (SD) age was 46.8 (16.6) years, and 422 (57.4%) were women. A total of 623 (84.8%) patients had COVID-19 symptoms, most commonly shortness of breath ( n  = 404; 55.0%), cough ( n  = 314; 42.7%), and fever ( n  = 253; 34.4%). Although 460 (62.6%) had symptoms ≤7 days, the mean (SD) time since symptom onset was 8.1 (14.0) days. Positive tests occurred in 173 (23.5%) and 141 (19.2%) with the gold standard versus BinaxNOW test, respectively. Those with symptoms >2 weeks had a positive test rate roughly half of those with earlier presentations. In patients with symptoms ≤7 days, the sensitivity, specificity, and negative and positive predictive values for the BinaxNOW test were 84.6%, 98.5%, 94.9%, and 95.2%, respectively. Conclusions: The BinaxNOW point-of-care test has good sensitivity and excellent specificity for the detection of COVID-19. We recommend using the BinasNOW for patients with symptoms up to 2 weeks. Competing Interests: Each author's institution received financial support for the performance of the study. (© 2022 The Authors. JACEP Open published by Wiley Periodicals LLC on behalf of American College of Emergency Physicians.)