Which is an interesting problem, isn't it? Not inviting people might be an option, one that doesn't provide any benefits, except an number of letters not being sent. So I'd say keep the invites, because every single additional person showing up for a screening is a net win. Additional educating efforts will definetly help so, no idea how those can look like so.
We can't say that from this study.
Colonoscopy does appear to be one of the screenings that reduces mortality. (That's why this is such a surprising result and is getting a lot of attention). But that does not mean that colonoscopy screening is useful for people in their 40s. There's a lot of discussion about the benefits and risks of colonoscopy screening for people in their 50s. Colonoscopy, especially as it's practised in the US with heavy sedation, is not risk free.
As it stands, this study, while statistically very good, doesn't help anything to answer the really important questions and only confuses people by causing discussions about the study methods, then used to derive conclusions about colonoscopies (utter nonsense, but first principle thinking using supporting science /domains is really en vogue at the moment) instead of discussing the usefulness of colonoscopies in increasing survivability, early detection and decreasing probability of colon cancer.
No, it doesn’t, because the two groups of people you’re comparing aren’t actually similar, and therefore any outcome difference can’t be tied to the intervention.
The difference in outcome between those two groups may merely be that the people who go through with the colonoscopy (not fun) are also willing to go through with their doctor’s recommendations on, say, diet restrictions (also not as fun!) so are healthier and have better outcomes.
Differences with what?
Not with the counterfactual where those people didn’t get a colonoscopy! (At least as far as I can tell from the results being discussed here.)
> every single additional person showing up for a screening is a net win.
Maybe. This study doesn’t tell us much about it.
