Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Aug:109:118-122.
doi: 10.1016/j.ijid.2021.07.010. Epub 2021 Jul 7.

Diagnostic accuracy of a SARS-CoV-2 rapid antigen test in real-life clinical settings

Sabrina Jegerlehner  1 , Franziska Suter-Riniker  2 , Philipp Jent  3 , Pascal Bittel  2 , Michael Nagler  4
Affiliations

Diagnostic accuracy of a SARS-CoV-2 rapid antigen test in real-life clinical settings

Sabrina Jegerlehner et al. Int J Infect Dis. 2021 Aug.

Abstract

Background: Laboratory tests are a mainstay in managing the COVID-19 pandemic, and high hopes are placed on rapid antigen tests. However, the accuracy of rapid antigen tests in real-life clinical settings is unclear because adequately designed diagnostic accuracy studies are essentially lacking.

Objectives: The aim of this study was to assess the accuracy of a rapid antigen test in diagnosing SARS-CoV-2 infection in a primary/secondary care testing facility.

Methods: Consecutive individuals presenting at a COVID-19 testing facility affiliated to a Swiss University Hospital were recruited (n = 1465%). Nasopharyngeal swabs were obtained, and the Roche/SD Biosensor rapid antigen test was conducted in parallel with two real-time PCR tests (reference standard).

Results: Among the 1465 patients recruited, RT-PCR was positive in 141 individuals, corresponding to a prevalence of 9.6%. The Roche/SD Biosensor rapid antigen test was positive in 94 patients (6.4%), and negative in 1368 individuals (93.4%; insufficient sample material in 3 patients). The overall sensitivity of the rapid antigen test was 65.3% (95% confidence interval [CI] 56.8-73.1), the specificity was 99.9% (95% CI 99.5-100.0). In asymptomatic individuals, the sensitivity was 44.0% (95% CI 24.4-65.1).

Conclusions: The accuracy of the SARS-CoV-2 Roche/SD Biosensor rapid antigen test in diagnosing SARS-CoV-2 infections in a primary/secondary care testing facility was considerably lower compared with the manufacturer's data. Widespread application in such a setting might lead to a considerable number of individuals falsely classified as SARS-CoV-2 negative.

Keywords: COVID-19 diagnostic testing; epidemiology; infections; severe acute respiratory syndrome coronavirus 2; transmission.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Flow chart of the patient selection process.
Figure 2
Figure 2
Diagnostic accuracy of the Roche/SD Biosensor rapid antigen test in a real-life clinical setting. 1465 consecutive individuals presenting at a COVID-19 testing facility affiliated to a university hospital between January and March 2021 were studied. Sensitivities and specificities are in relation to RT-PCR, and are given for the overall study group as well as for salient subgroups.
Figure 3
Figure 3
Sensitivities of the rapid antigen test in relation to adapted cycle thresholds (CT) of RT-PCR. The manufacturer's recommended CT is 40.
See this image and copyright information in PMC

References

    1. Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig L, et al. STARD 2015: an updated list of essential items for reporting diagnostic accuracy studies. BMJ. 2015;351:h5527. - PMC - PubMed
    1. Bossuyt PMM. In: Evidence-based laboratory medicine. Second Edition. Price CP, Christenson RH, editors. AACC Press; Washington DC: 2007. Studies for evaluating diagnostic and prognostic accuracy; pp. 67–81.
    1. Brigger D, Horn MP, Pennington LF, Powell AE, Siegrist D, Weber B, et al. Accuracy of serological testing for SARS-CoV-2 antibodies: first results of a large mixed-method evaluation study. Allergy. 2021;76(3):853–865. - PMC - PubMed
    1. Bujang MA, Adnan TH. Requirements for minimum sample size for sensitivity and specificity analysis. J Clin Diagn Res. 2016;10(10):YE01–YYE6. - PMC - PubMed
    1. CDC. Coronavirus self-checker; 2020. Available from: https://www.cdc.gov/coronavirus/2019-ncov/.

Substances