There are serious differences between antigen tests, rapid tests, lay tests and PCR tests, which are not immediately obvious.
For example, a PCR test or antigen test is often requested because it has better sensitivity and specificity. However, the user often prefers the layman's test. This saves the time-consuming journey and testing in a test centre or at the doctor's office. Most lay tests are often also much more convenient to use because they only require a dressing depth of 2 to 4 cm, while thoroughly performed PCR tests require a dressing depth of 8 to 10 cm.
Inadequate dressing depth or incorrect performance increases the likelihood of inconclusive test results.