Understanding False Positive COVID Screening Results

Earlier this week, in the midst of a wildly stressful couple of weeks, I got a rude red “positive” light on the Metrix reader running my COVID-19 test. These tests have a 99% specificity (i.e., they give a negative result for 99% of samples that don’t have COVID in them). So from a naïve perspective, it would seem that seeing the red “positive” light on the reader would mean there was only a 1%…