2 ms·
Here's an easy to read introduction to over-testing and over-diagnosis. This isn't talking about false postives. It's talking about harm caused by actual positi
by DanBC 7y ago
Here's an easy to read introduction to over-testing and over-diagnosis. This isn't talking about false postives. It's talking about harm caused by actual positives. https://ebm.bmj.com/content/23/1/1 https://ebm.bmj.com/content/23/1/1
Gerd Gigerenzer has done a lot of work on this, so his books are useful. Reckoning With Risk or Risk Savvy are good.
> What I would prefer to see is that screening comes with patient education so they understand the potential risks and inaccuracies and then let 'er rip. If something goes south, it's on them.
Informed choice should already be built into all healthcare systems because it's a feature of international human rights laws and patients are usually allowed to decline to have a test done. And there's usually a doctor somewhere who'll perform an unnecessary test if you're prepared to pay.
Communicating risk is difficult.
We know that merely giving people information and letting them take full responsibility won't work. We know it won't work because we already study whether people understand the risks of testing and treatment, and we find a disturbingly large number of people don't, and that includes the HCPs recommending the testing and treatments.
Most people struggle with this question: "A machine has been invented to scan a population for a disease. The machine is good but not perfect. If you have the disease there is a 90% chance it will return positive. If you do not have the disease there is a 1% chance it will return positive. About 1% of the population have the disease. Mr Smith is tested, and the test comes back positive. What's the chance Mr Smith actually has the disease?"
But the problem of lack of numeracy is more severe: only 20% - 25% of people understand that 0.1% is 1 in 1,000. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310025/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310025/
People do not understand the difference between "absolute" vs "relative" risk increases, so we see newspapers reporting "100% increase in risk from eating X" when the numbers are an increase from 1:100,000 to 2:100,000 deaths.
https://bestpractice.bmj.com/info/toolkit/practise-ebm/understanding-risk/ https://bestpractice.bmj.com/info/toolkit/practise-ebm/under...
https://www.eufic.org/en/understanding-science/article/absolute-vs.-relative-risk-infographic https://www.eufic.org/en/understanding-science/article/absol...