If the tests are cheap and can be performed as frequently as necessary, I could imagine a system where a test isn't considered positive until a statistically significant number of them have come back positive. If there is an abundance of data, there is no longer a need to extrapolate from a single data point.

I had a blood test once where my electrolytes were somewhat out of whack. I wasn't called in for an expensive kidney scan or consultation with a urologist. I was called in for another blood test. The second test came back fine. I was likely dehydrated the day of the first test.

The availability of cheaper, more frequent testing means that the response to a single positive signal does not have to be as extreme. Thankfully my doctors office offers walk-in blood testing or my experience could've been a much more anxiety-inducing hassle.