Head-to-head comparison of the accuracy of saliva and nasal rapid antigen SARS-CoV-2 self-testing: cross-sectional study

• DOI: 10.1186/s12916-022-02603-x
• Publication Date: 2022-10-24T13:03:48Z
• Authors: Ewoud Schuit; Roderick P. Venekamp; Irene K. Veldhuijzen; Wouter van den Bi...; Suzan D. Pas; Joep J. J. M. Stohr; Esther B. Lodder; Marloes Hellwich; Richard Molenkamp; Zsofia Igloi; Constantijn Wijers; Irene H. Vroom; Carla R. S. Nagel...; Wanda G. H. Han; Jan A. J. W. Kluy...; Susan van den Hof; Janneke H. H. M. ...; Karel G. M. Moons
• Keywords: Cross-sectional study; Point-of-Care Testing

Abstract Background The diagnostic accuracy of unsupervised self-testing with rapid antigen tests (Ag-RDTs) is mostly unknown. We studied the a self-performed SARS-CoV-2 saliva and nasal Ag-RDT in general population. Methods This large cross-sectional study consecutively included unselected individuals aged $$\ge$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>≥</mml:mo> </mml:math> 16 years presenting for testing at three public health service test sites. Participants underwent molecular sampling received two self-tests (the Hangzhou AllTest Biotech self-test SD Biosensor by Roche Diagnostics) to perform themselves home. Diagnostic both was assessed as reference. Results Out 2819 participants, 6.5% had positive test. Overall sensitivities were 46.7% (39.3–54.2%) 68.9% (61.6–75.6%) Ag-RDT. With viral load cut-off (≥ 5.2 log10 E-gene copies/mL) proxy infectiousness, these increased 54.9% (46.4–63.3%) 83.9% (76.9–89.5%), respectively. For Ag-RDT, 78.5% (71.1–84.8%) 22.6% (9.6–41.1%) those symptomatic asymptomatic time sampling, which 90.4% (83.8–94.9%) 38.9% (17.3–64.3%) after applying cut-off. In without prior infection, 36.8% (16.3–61.6%) 72.7% (65.1–79.4%). Specificities &gt; 99% 99%, predictive values 70% 90%, negative 95% 95%, respectively, most analyses. Most participants considered self-performing result interpretation (very) easy self-tests. Conclusions self not reliable detection, overall, all subgroups. high sensitivity symptoms infection but low warrants further investigation.