Exactly -- for those 45% with the false positive, you will be doing emotional harm to many of them, even without an invasive followup test.
And then, if you knew that 45% of people got a false positive, how likely is the 5% (the true positives who really need it) going to believe their initial result and even get the followup?
EULA and UI should emphasize that this is not a sure thing, please see a doctor to be sure. Why would anyone get mad at that? My grandpa noticed my dad losing a ton of weight. He told my dad there might be something wrong with him, go check it out. Turns out it was cancer, saved my dad's life. Should my dad be upset at my grandpa for causing emotional stress if it was nothing?
Of course your dad shouldn’t be upset - your grand father did exactly what he should have done. When you notice a symptom like that, you get it checked out. (I’m happy for you and your dad, btw). The problem is when you have people getting checked out without any underlying symptoms.
When you have a ton of people getting their hearts checked because their watch told them to (and only for that reason), you’re going to get a lot of false positives. There are many reasons better explained in these comments for why that’s not a good thing.
One major reason is the extra stress on the medical system that can’t handle it. There has been much talk about medical genetics clinics having issues dealing with people calling in about 24 and me (etc) test results. It’s a major load for these clinics.
Now, an easy test like this — in the presence of other symptoms — is a great thing to have. I just worry about all the people getting needlessly checked out. But for those who already have a concern or family history, this type of test can be great.
Getting tests when you have symptoms is a completely and totally different topic than widescale testing of asymptomatic individuals without specific risk factors, which is what we are talking about here.
