Lies, damn lies, and statistics

[ZenGum]

I have seen this issue before, couched in terms of doctors not understanding the statistics of false positives.

Part of the problem is that the simple statement "false positive rate of 7%" is ambiguous.
It might be takes as:
7% of positive tests are false,
7% of false tests are positive or
7% of tests of negative subjects will falsely show positive.
The third is the correct interpretation but the first is the most common one.

The further point about comparing the likelihood of a false positive with the likelihood of actually having the condition is still valid.