The Perfect Enemy | Study: COVID-19 rapid home tests not highly sensitive for Omicron
December 3, 2022

Study: COVID-19 rapid home tests not highly sensitive for Omicron

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Dutch researchers reveal that the sensitivities of three commonly used rapid antigen tests, when used in asymptomatic people in the Omicron period, were very low and suggest repeat testing after a negative test. The study is published in Clinical Microbiology and Infection.

The study was conducted between Jan 2 to Mar 30, 2022, when Omicron accounted for 90% to 99.5% of all cases in the Netherlands. A total of 3,600 asymptomatic people with suspected COVID-19 were tested using one of three at-home rapid antigen tests and a reverse-transcription polymerase chain reaction (RT-PCR) test. Home tests were provided within 3 hours of taking an RT-PCR test.

Overall sensitivities for the three home tests were 27.5% (95% confidence interval [CI], 21.3% to 34.3%) for Flowflex, 20.9% (95% CI, 13.9% to 29.4%) for MPBio, and 25.6% (95% CI, 19.1% to 33.1%) for Clinitest. After applying a viral load cut-off, sensitivities increased to 48.3% (95% CI, 37.6% to 59.2%), 37.8% (95% CI, 22.5% to 55.2%), and 40.0% (95% CI, 29.5% to 51.2%), respectively.

Participants with negative tests also filled out a questionnaire, which showed 54.8% retested in the 10 days following a negative test, with 24.6% testing positive.

The positive predictive values were greater than 92%, and negative predictive values were greater than 88% for all self-tests. The authors said previous studies on self-tests conducted before Omicron yielded better sensitivities, at 52.5% in asymptomatic individuals.

“We conclude that SARS-CoV-2 self-testing has limited value for asymptomatic individuals wishing to protect vulnerable persons and may even lead to a false sense of security,” the authors concluded. “The high SARS-CoV-2 infection rate within 10 days of a negative RT-PCR test that we found in our study emphasizes the importance of re-testing over time, especially when symptoms develop, to reduce missed infections as much as possible.”