Every time you test a disease free individual there is some chance that that test will result in a false positive. A lower prevalence means more of the people tested will be disease free. Mathematically this must lead to a higher rate of false positives.
What a beautiful explanation! Amazing!
that was super useful, ty (am a nurse looking after covid patients most shifts, so this helped me understand their test results)
Glad you found it helpful. Thanks for letting me know!
Sir how does low prevalence increase false positive?
Every time you test a disease free individual there is some chance that that test will result in a false positive. A lower prevalence means more of the people tested will be disease free. Mathematically this must lead to a higher rate of false positives.
@@SciencePrimer thank you sir it's clear now 😊👍
I cannot for the life of me understand why PPV and NPV are influenced by prevalence but LR+ and LR- are not