If having more information leads to worse outcomes, that's fundamentally a problem with how you're responding to the information, not with having the information.
Not necessarily.
Rohin Francis (Medlife crisis) has I think a video on overtesting, but for example, if you have a new technology that tests and suspects a tumor, which results in CT scans for patients, if millions of users use this tech there's a likely non-zero number of people who may get cancer from the CT exposure.
"What about those who actually had the tumor?"
Well it's possible that 99% of these cases would've been symptomatic anyway in a few more months.
By explanation isn't the best, but over-medication is not a non-issue.
Then you can decide whether a test makes sense or doesn't make sense, given the tradeoffs of radiation and cost vs. the risks of harm.
In the real world, information absolutely can lead to harm, but it's still all in the response and how medicine and patients use information.
But as information gets cheaper and more common we can develop ways of dealing with it. If it was difficult and expensive to test for fever you'd see people in the medical profession warning against it because it could lead to overreaction.
Another thing I seem to remember in his video was that a tumor is not necessarily dangerous. Out of a hundred (say) tumors in a person's life, only maybe 5 are risky. But I'm paraphrasing this badly.
Edit: https://www.youtube.com/watch?v=7kQk9-KLPfU is one of the videos, however I think he's talked about this more (likely on instagram or another video too).
>For a lot of people, if you get a positive result from a test that a doctor brushes off that's not going to go well.
This is precisely because of the rarity of testing. Suppose the cost of testing dropped 1000x and we could get tests for things each day or each month. We'd start to have systems that put these things on context.
When you have a single isolated result there really isn't that much to go on.