The court stated that the test's reliability depends on the number of cycles used and the viral load present and concluded that "if someone is tested by PCR as positive when a threshold of 35 cycles or higher is used (as is the rule in most laboratories in Europe and the US), the probability that the individual is infected is less than 3%, and the probability that said result is a false positive is 97%."

The case was brought to court after four people had been quarantined by the Regional Health Authority. Of these, only one had tested positive for COVID using a PCR test, and the other three were deemed to have been at high risk for exposure, which required all four of them to go into isolation.

On November 11, 2020, a Portuguese appeal court ruled it was unlawful to quarantine people based solely on a PCR test.