3 ms·

Early in the pandemic, absolutely. It was easier/quicker to test for the flu and rule out covid, than test for covid to rule out the flu.

• meragrin_ 6y ago
  How does testing positive for the flu rule out covid? What is to prevent someone from having both?
  • GavinMcG 6y ago
    No idea on the technical answer, but the healthcare logistics answer is that because it's not all that likely, a positive flu test was a decent stand-in when COVID tests weren't widely available.
  • jtolmar 6y ago
    Say 1 in 10 people have flu and 1 in 10 have covid. In a population of 100, 9 have just flu, 9 have just covid, and 1 has both. Those 19 people present similar symptoms, and anyone among them has roughly a 53% chance of having each disease. They take a flu test and it comes up positive. Now they're either one of the 9 with just flu, or the one unlucky person with both, so there's only a 10% chance they have covid. The impact of this effect changes if has-flu and has-covid are correlated, but it's still there unless it's a 100% correlation.
  • Matumio 6y ago
    The technical term is "explaining away". If a burglar alarm goes off, you can be pretty sure someone triggered it. If there also was an earthquake at the same moment, you can be pretty sure of the opposite. Even though both events can happen at the same time.