I was going to post the same thing – Poland launched a nationwide campaign two years ago to get all people over 50 years old (above 40 if they had family history) in for a colonoscopy. However, the linked article is working with a European study done a decade ago (EDIT: I’m wrong about that). There may have once been greater differences between American and European approaches.
There would be an reduction of 37% in diagnoses if everyone would have accepted the treatment (but no data for mortality).
How significant is reducing a small risk (1%) significantly?
(Base rate fallacy)
"The right graph compares those results to the observed outcomes for acceptors in our branch of the multiverse, where they did have colonoscopies. At the end of the trial, there’s a reduction of 37%. Unfortunately, data aren’t available to do this for mortality,..."
tl;dr - healthy individual without family history could be more likely to refuse the screening (less refuses were diagnosed with CRC than the control). This is the reason the study can't omit refuser from calculations.
I have seen the data for mortality before in at least one publication if not more, and it clearly showed that the increase rate in diagnosis did not result in improved outcomes for survival, which is precisely why colonoscopy has a very bad ROI right now
