4 ms·

> But these are luxuries and if you ask most doctors, you'll get back "you look great why would you do that?", aka, come back when you're sick. Proactive tests

by Swizec 2y ago

> But these are luxuries and if you ask most doctors, you'll get back "you look great why would you do that?", aka, come back when you're sick. Proactive tests are great! Except for the false positive challenge. If the test has a 99% accuracy and it detects a problem that presents in 0.1% (1 in 1000) of general population, do you have the issue? Should you do something about it? Well it turns out you only have a 3% (my math is likely imperfect) chance of actually having the thing you tested for unless you also have other symptoms. Now what do you do about it? Unnecessary medical interventions kill people all the time. Prostate cancer is a great example here. If you’re over 30 and male, you very likely have a little bit of detectable prostate cancer. But you’re fine just leaving it alone for another 30 years and there’s a huge likelihood it’s never going to become a problem at all. Getting it fixed would be way worse for you than leaving it alone. (1 in 8 men eventually gets diagnosed with this meaning way more actually have it)

Palomides 2y ago
the test isn't the problem, it's that doctors and patients aren't used to making decisions based on probability (patients demand something must be done, while doctors run on vibes and cover your ass) (context: spent some time working in a prostate cancer research lab and have doctors in the family)
- deleted 2y ago
  [deleted]
cameronh90 2y ago
It's funny that we only apply this "more data = bad" logic to things that aren't readily visible. If you have a palpable or visible likely-benign condition that isn't causing symptoms, such as a mole, rash, or lump, every doctor will recommend getting that checked out. Most of the time it'll turn out to be completely innocuous, but you'll go to the doctor and they'll decide between it's fine, monitoring, invasive investigation, and urgent treatment. Obviously if the test itself is invasive (e.g. has a dose of radiation) then that is something that needs to be compared against the potential benefit. I certainly would not have a preventative head CT scan. However if we're talking about things like an MRI, urine/stool test, or even something like a blood panel that has extremely low risks for most apparently healthy people (I donate blood 6x a year anyway - why not take some of that and test it), then why is it so different to a skin check, besides the cost?
- apwell23 2y ago
  > Obviously if the test itself is invasive (e.g. has a dose of radiation) then that is something that needs to be compared against the potential benefit. A test isn't always a binary 'you have X ' . Look at PSA screening for prostate cancer starting in your 40s is not recommended for that reason.
  - cameronh90 2y ago
    I'm aware but also not sure how that changes anything. Say you're 40 and you get a positive PSA result, maybe that means your risk of having prostate cancer has gone from (for illustrative purposes) 0.1% to 2%. That means the next step is "what do you do to someone who has a 1 in 50 chance of having prostate cancer?", and the answer is almost certainly not a biopsy or anything majorly invasive. The answer might be a finger up the butt, an MRI, monitoring for symptoms, repeat the test in a year, etc. The problem is that patients aren't used to handling these ambiguous results from tests because we don't do much routine testing, and doctors don't want to face the potential consequences for getting a positive test result and recommending against invasive treatment. However, in many cases, a test would still tell you something useful even if it won't directly be used to escalate to a more invasive test or treatment. For example, if a routine blood test shows prediabetes (which has happened to a few people I know when having blood tests for unrelated matters), you won't get any treatment for it, but you may be referred to a dietician and have a fire lit up under your ass to make those lifestyle changes you've been putting off.

by Swizec 2y ago

Palomides 2y ago

the test isn't the problem, it's that doctors and patients aren't used to making decisions based on probability (patients demand something must be done, while doctors run on vibes and cover your ass) (context: spent some time working in a prostate cancer research lab and have doctors in the family)

deleted 2y ago
[deleted]

cameronh90 2y ago

It's funny that we only apply this "more data = bad" logic to things that aren't readily visible. If you have a palpable or visible likely-benign condition that isn't causing symptoms, such as a mole, rash, or lump, every doctor will recommend getting that checked out. Most of the time it'll turn out to be completely innocuous, but you'll go to the doctor and they'll decide between it's fine, monitoring, invasive investigation, and urgent treatment. Obviously if the test itself is invasive (e.g. has a dose of radiation) then that is something that needs to be compared against the potential benefit. I certainly would not have a preventative head CT scan. However if we're talking about things like an MRI, urine/stool test, or even something like a blood panel that has extremely low risks for most apparently healthy people (I donate blood 6x a year anyway - why not take some of that and test it), then why is it so different to a skin check, besides the cost?

apwell23 2y ago
> Obviously if the test itself is invasive (e.g. has a dose of radiation) then that is something that needs to be compared against the potential benefit. A test isn't always a binary 'you have X ' . Look at PSA screening for prostate cancer starting in your 40s is not recommended for that reason.
- cameronh90 2y ago
  I'm aware but also not sure how that changes anything. Say you're 40 and you get a positive PSA result, maybe that means your risk of having prostate cancer has gone from (for illustrative purposes) 0.1% to 2%. That means the next step is "what do you do to someone who has a 1 in 50 chance of having prostate cancer?", and the answer is almost certainly not a biopsy or anything majorly invasive. The answer might be a finger up the butt, an MRI, monitoring for symptoms, repeat the test in a year, etc. The problem is that patients aren't used to handling these ambiguous results from tests because we don't do much routine testing, and doctors don't want to face the potential consequences for getting a positive test result and recommending against invasive treatment. However, in many cases, a test would still tell you something useful even if it won't directly be used to escalate to a more invasive test or treatment. For example, if a routine blood test shows prediabetes (which has happened to a few people I know when having blood tests for unrelated matters), you won't get any treatment for it, but you may be referred to a dietician and have a fire lit up under your ass to make those lifestyle changes you've been putting off.