[DanBC]

Risk does need to be presented both ways - relative and absilute - for anyone to make any sense of it though.

People see 50% increase in risk and don't have enough information to make an informed choice. If you tell them that we go from 2 people in a thousand suffering ill effects to 3 people in a thousand they can make their choice.

See the work of Gerd Gigerenzer for plenty of examples of people caused harm because they were told only the relative risk.

[elif]

But in this case, the extra variable adds weird implications that are simply not true...

For instance, if half of the population became vegetarians, the rate of colorectal cancer would go down, and red meat would become even more "safe."

[DanBC]

People aren't saying that.

They're saying if you have a population of 1,000 people who don't eat red meat you'd expect to see 2 cases of DISEASE_X. If you take a similar population but who do eat red meat you'd expect to see 3 cases of DISEASE_X.

That's a 50% increase, but that 50% relative risk number isn't enough information for people to make any decision. Here we're talking about an extra 1 person in 1000 people. But if the numbers were 4 in 10 increasing to 6 in 10 that's still only a 50% increase.

We need the absolute risk numbers to get an understanding: 0.2% increases to 0.3%. Something that's unlikely to happen becomes marginally more likely to happen.

This is not some weird obscure trickery. It's an important thing for people receiving healthcare to understand. It's mainstream science.

https://bestpractice.bmj.com/info/toolkit/practise-ebm/under...

https://www.eufic.org/en/understanding-science/article/absol...

Have a look at the factbox and the icon array linked in this page: https://www.harding-center.mpg.de/en/fact-boxes/early-detect...

But also, we should avoid using percentages and we should use natural frequencies.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310025/ Only about 1 in 4 people understand that 0.1% means 1 in 1000.