The meme is talking about a common probability error that surveys have shown even doctors are prone to making.
Why you’re probably ok:
The rarity of the disease far exceeds the error rate of the positive test. Meaning, the disease occurs in 1 out of a million people, so if you are tested at random and show positive, you only have a 1 out of 30,000 chance (the 3% false-positive rate) of being the the 1 person who truly has the disease.
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The doctor is the one with the correct reaction there. Go do the second test.
I mean, yes…
But at 1/30,000 , they should say “get the second test… but be SUPER CAREFUL on the drive”, since at 1/30000 you’re still an order of magnitude more likely to die in an MVA.
This is ideal bedside manner.
I’ve always thought that I’d make an exceptional professional in the field of medicine.
The only thing really holding me back is my unfathomable depth of ignorance regarding the human body, or health in general.
At one point in my life, I believed that to be a deal breaker. Cheers, RFK Jr.
This is one of the main reasons doctors don’t ‘just give you a battery of tests’. Not only is that expensive, but if you are running dozens of tests, the chance one of them gives a false positive is pretty high. So now you not only wasted a pile of money, but you also think you have some rare disease you don’t actually have. So you waste even more time and money treating that disease you don’t have.
Doctors run tests for things they think you might actually have, which diminishes the false positive chance.
I have been thinking about this for a while.
Would this actually diminish the false positive rate for the test? Would it just be more likely to get a true positive back?
Or maybe would the false negative result be less likely?
Does it depend on the sample group that was measured to get the accuracy statistics? If the sample group was random then does that actually make a difference?
Doing my head in
Accuracy and False Positive Rates are two different numbers.
I’m tired and my brain is being dumb right now, but when you said that my first thought was of course American. 97% accuracy grouping bullets is a lot different than 97% sure a gun was fired.
One says Johnny got shot in the kidney, the other says a truck may have misfired down the road.
Alright since I am actually currently learning about Bayes theorem. Assuming 97% accuracy means 3% chance of false negative and false positive. If you test positive. You have a 0.0032% of actually having the disease. If someone wants to double check me I encourage it.
Tactical RPGs have basically taught me that anything below 100% is almost always a miss and even 100% isn’t guaranteed.
I missed a very important 96% shot in XCOM last night. I’m still thinking about it.
What statistician is this referring to? Certainly not one who understands probabilities. The first number has nothing to do with it. You tested positive, and there’s only a 3% chance that result is wrong. Time to settle your affairs.
https://en.wikipedia.org/wiki/Thomas_Bayes This guy. The guy who arguably set in motion the modern approach to statistical theory.
