Bad quick test results: Almost a third showed false positive results in the examination - RKI provides classification

For many people, the rapid test is currently part of everyday life.

To live a touch of normalcy.

But the security it promises can be deceptive.

Munich / Hamburg - you should actually ensure certainty and thus ultimately more security. In addition to the vaccinations, the corona tests also fed hope for a way out of the eternal lockdown months. Self-tests have been available in drug stores and supermarkets for a few weeks now. Many employers offer corona tests to their employees who, for whatever reason, cannot work from home. And anyone who prepares for the date shopping that became fashionable in the Corona era, for example, also needs a negative result.

But the rapid tests don't seem nearly as reliable as they appeared when they were first introduced.

The risk of a negative result due to a low viral load in the body could never be discussed away.

But an investigation has now also revealed a significant proportion of false-positive tests.

Incorrect corona test results: In Hamburg, 31.5 percent of positive tests were incorrect within three weeks

Between March 22 and April 11, the Hamburg Senate recorded a total of 2035 positive rapid test results that were reported to the health authorities.

The subsequent PCR tests, however, only confirmed the findings in 68.5 percent of the cases.

Conversely, this means: 31.5 percent of positive rapid tests spat out a wrong result.

The government of Hamburg's First Mayor Peter Tschentscher (SPD) responded with the disclosure to a small request from the CDU parliamentary group.

Hundreds of thousands of tests are now being carried out every week, it continues.

A more up-to-date comprehensive investigation seems impossible.

"A complete monitoring of all rapid tests carried out in the city beyond the test centers is not feasible due to the large number of different, also private and other areas that carry out these tests," explained the Senate.

Video: How do I behave properly after a positive test result?

Incorrect corona test results: RKI points out problems with the rapid tests

The Robert Koch Institute itself emphasizes that the rapid tests, compared to PCR tests, would detect “both infected people worse (lower sensitivity) and non-infected people worse (lower specificity)”.

It goes on to say: "The informative value of rapid antigen tests depends heavily on the proportion of infected people among the people tested (pre-test probability) and on the sensitivity and specificity of the tests."

Brief explanation of terms: Sensitivity is understood to mean “the proportion of people with a positive test result among those infected”.

The specificity means the "proportion of people with a negative test result among the non-infected".

Basically, the "positive test results are unreliable" for a few actually infected people among those tested, but "positive test results are reliable" for many infected people, and "the negative test results are less". In short, “test approach” and “spread of the virus” are decisive.

(mg)