https://www.independent.co.uk/life-style/health-and-families/features/why-i-m-saying-no-to-a-smear-7577967.html
And this interview is interesting:
https://www.sefap.org/2014/09/24/interview-with-margaret-mccartney-the-waste-and-harm-of-overdiagnosis/
-M.M.: This is the “popularity paradox”. The worse a screening test is, the more false positives there are; the more false positives there are, the more people are led to believe that a screening test saved their life. So the paradox is that the poor screening test becomes more popular, as people are led to believe that they have been saved, not harmed, by it.
She's saying that screening is driven a lot by peer pressure and people coming along saying 'you should have your test, my test saved my life'.
Except the paradox is that lots of these people, didn't have their life saved. They had unnecessary treatment. But they will never know their treatment was unnecessary because of how this works. They just believe their life was saved rather than understanding they might have been one of those who had actually been harmed by screening.
It's a difficult thing to get your head around. Its's an uncomfortable thought that many of those who are 'walking adverts for the success of screening' are actually the unwitting unaware victims of harms done by screening. Certainly no one who may have gone through that will want to consider they've potentially been harmed rather saved. Psychologically it doesn't compute.
Her point is that some of these numbers when assessing risk are massively off.
If the risk across the population as a whole is 1 in 2000, this isn't an evenly spread thing. Certain conditions are very much part of a pattern of family history. So if you have a family history of a certain cancer your risk is actually much higher than that 2000, but the reverse is also true if there isn't that pattern. And this massively distorts 'the risk' you are presented with.
Thus if you are armed with this knowledge about risk not being evenly spread, you might make different decisions. People with a family history might take it much more seriously whereas other might go, actually that risk is really really small, is it worth taking the risk of harm because that's actually a lot higher for me all things considered and I also might wish to consider the impact of the actual procedure itself to my mental health.
Thus being MORE informed can lead to patients deciding they don't want to consent in certain situations.
The whole discussion around presentation of risk is a fascinating one. I do recommend reading up CAREFULLY about what she says in full. Everyone should read the Patient Paradox even though it's now quite an old book now - it's still hugely relevant today. It's one of those books which is hugely important (Ben Goldacre's books are better known about big pharma and science more generally, but it's the same principle).
She talks a lot about the misogynistic nature of the promotion of screening programmes to women too and how they are potentially very unethical and rely on coercive techniques and the infantilisation
and patronising of women which doesn't happen in the same way to men.
It's a fascinating subject, and I really can't help feel we haven't moved on at all since she wrote it.