Self-tests without Covid symptoms often inaccurate: study

During the period when the Omicron variant of the coronavirus was dominant, the accuracy of three commercially available self-tests was low for people without coronavirus symptoms. Research showed that if people without complaints did a self-test, 72 to 80 percent of the infected people did not test positive.

It was already known that self-tests are sufficiently reliable in people who do have coronavirus-like symptoms.

A large group of Dutch researchers examined three commercially available and often-used coronavirus self-tests from Acon Labs (Flowflex), MP Biomedicals (MPbio), and Siemens-Healthineers (Clinitest) on more than 3,600 people without coronavirus symptoms. The study was conducted from January 12 to March 30 this year, when the Omicron variant was clearly dominant in the Netherlands. At the test sites, the participants underwent a PCR test to determine whether they were infected. They then received one of the three self-tests to use at home within three hours of the site visit, without knowing the results of the PCR test.

The researchers called the outcome of their study important for situations in which the authorities must decide whether or not have symptomless people use self-tests. They advise people without complaints who got negative results from such a test to repeat the self-test if they are among vulnerable people, for example, a day after the first test.

The research also showed that it is still important to observe the basic hygiene measures to protect vulnerable people - social distancing where possible, good ventilation, the use of a face mask, and coughing or sneezing into the elbow instead of the hands.