Rapid Covid Test False Positive Rate. In total, 462 rapid test results, or 0.05 per cent of the 900,000 results, resulted in false positives. Rapid antigen tests are highly specific, which means that they generate relatively few false positives.

It's much higher — nearly 100 percent — when they're tested before that, though. True positive, true negative, false positive, and false negative. Some studies have found that up to 29 percent of these tests can give false negatives.