3 ms·

Seems like having more data can only be a good thing (modulo any degree to which the scan itself has the potential to cause damage), but it's going to make it m

Seems like having more data can only be a good thing (modulo any degree to which the scan itself has the potential to cause damage), but it's going to make it much more important to be cautious of false positives, as well as to not automatically assume that every potential issue is worth addressing and has no tradeoffs that would motivate choosing to handle it differently.

seizethecheese 3y ago
There’s only no harm in more data if you handle false positives perfectly. Surely, this is never the case, so there’s always some harm in more data.
- Bukhmanizer 3y ago
  I’ve heard it’s quite hard to handle due to lawsuits and such. E.g if you get a scan and they find something that’s benign 99.99% of the time, if it does happen to be malignant, you’re going to find yourself in court.
- whateverman23 3y ago
  > There’s only no harm in more data if you handle false positives perfectly. Surely, this is never the case, so there’s always some harm in more data. That's not the correct way to think about it. The correct way to think about it is whether or not there's more harm with more data than the status quo. Most medical professionals seem to think there's more harm than the status quo, but that doesn't change the fact that you're thinking about it wrong.
- JoshTriplett 3y ago
  What I'm suggesting is that the harm is not, then, in having the data; the harm is acting on it in ways that make you worse off than if you hadn't acted, without considering false positives and without considering possible harms caused by the selected treatment.
  - tptacek 3y ago
    Your doctor may not have much of a choice but to follow up on anomalies discovered during diagnostic scans, so you need to factor in your willingness to overrule your doctor.
    - robwwilliams 3y ago
      Yep! Physicians are motivated to treat pre-emptively, not wait and find out. It is much easier to say after surgery: “All is good; no cancer, we took out a small bleb of tissue we thought was a tumor” than to say “Sorry, we thought that was a benign growth and that is why we did not recommend surgery 6 months ago, but it turns out we were wrong—it was a malignant tumor that has now spread.”
    - drcode 3y ago
      Yes, our medical system is still in the stone age when it comes to correctly handling statistics (source: am doctor)
  - edmundsauto 3y ago
    This strikes me a little like the rational economic model of criminals, i.e. they weigh the cost of getting caught * likelihood against benefit of the crime. In reality, having data people are biased towards action. But I agree, a holistic interpretation - including the population level "bad decisions" - is the ultimately correct approach. The caution I would urge is not to allow "no true scotsman" arguments, ie "well it's a good thing as long as people are careful". Many people aren't going to be, which is part of the calculus.
  - drcode 3y ago
    You are 100% correct in your thinking (I'm a medical doctor btw) For some reason many people will argue ad nauseum that this very obviously true and simple fact isn't true
oldgradstudent 3y ago
Some people believe in data like other people believe in God. Data is meaningless without context and without knowing how reliable it is. PSA tests, for example, provide data that sent a lot of people to an early grave, or to years of unnecessary treatment and anxiety.
- sseagull 3y ago
  Kinda related story about data and context: I saw a discussion on a website (ask a doctor type of stuff). A guy found that a lymph node in his neck seemed a little big. He found an academic article that stated about 50% of lymph nodes over a particular size at that location were cancerous, and he was panicking. He was gently informed by a doctor that he was missing an important context about the paper. I think about that a lot when people in various forums (including this one) cite academic papers or other information from areas they aren't experts in. They may be correct (technically correct), and have the correct data, but context might they be missing? (The 50% number was of samples sent to a lab. Doctors aren't in the habit of taking random healthy people's lymph nodes and sending them for biopsy, so those patients had other symptoms of lymphoma that triggered the need for a biopsy of suspicious lymph nodes.)

seizethecheese 3y ago

There’s only no harm in more data if you handle false positives perfectly. Surely, this is never the case, so there’s always some harm in more data.

Bukhmanizer 3y ago
I’ve heard it’s quite hard to handle due to lawsuits and such. E.g if you get a scan and they find something that’s benign 99.99% of the time, if it does happen to be malignant, you’re going to find yourself in court.
whateverman23 3y ago
> There’s only no harm in more data if you handle false positives perfectly. Surely, this is never the case, so there’s always some harm in more data. That's not the correct way to think about it. The correct way to think about it is whether or not there's more harm with more data than the status quo. Most medical professionals seem to think there's more harm than the status quo, but that doesn't change the fact that you're thinking about it wrong.
JoshTriplett 3y ago
What I'm suggesting is that the harm is not, then, in having the data; the harm is acting on it in ways that make you worse off than if you hadn't acted, without considering false positives and without considering possible harms caused by the selected treatment.
- tptacek 3y ago
  Your doctor may not have much of a choice but to follow up on anomalies discovered during diagnostic scans, so you need to factor in your willingness to overrule your doctor.
  - robwwilliams 3y ago
    Yep! Physicians are motivated to treat pre-emptively, not wait and find out. It is much easier to say after surgery: “All is good; no cancer, we took out a small bleb of tissue we thought was a tumor” than to say “Sorry, we thought that was a benign growth and that is why we did not recommend surgery 6 months ago, but it turns out we were wrong—it was a malignant tumor that has now spread.”
  - drcode 3y ago
    Yes, our medical system is still in the stone age when it comes to correctly handling statistics (source: am doctor)
- edmundsauto 3y ago
  This strikes me a little like the rational economic model of criminals, i.e. they weigh the cost of getting caught * likelihood against benefit of the crime. In reality, having data people are biased towards action. But I agree, a holistic interpretation - including the population level "bad decisions" - is the ultimately correct approach. The caution I would urge is not to allow "no true scotsman" arguments, ie "well it's a good thing as long as people are careful". Many people aren't going to be, which is part of the calculus.
- drcode 3y ago
  You are 100% correct in your thinking (I'm a medical doctor btw) For some reason many people will argue ad nauseum that this very obviously true and simple fact isn't true

oldgradstudent 3y ago

Some people believe in data like other people believe in God. Data is meaningless without context and without knowing how reliable it is. PSA tests, for example, provide data that sent a lot of people to an early grave, or to years of unnecessary treatment and anxiety.

sseagull 3y ago
Kinda related story about data and context: I saw a discussion on a website (ask a doctor type of stuff). A guy found that a lymph node in his neck seemed a little big. He found an academic article that stated about 50% of lymph nodes over a particular size at that location were cancerous, and he was panicking. He was gently informed by a doctor that he was missing an important context about the paper. I think about that a lot when people in various forums (including this one) cite academic papers or other information from areas they aren't experts in. They may be correct (technically correct), and have the correct data, but context might they be missing? (The 50% number was of samples sent to a lab. Doctors aren't in the habit of taking random healthy people's lymph nodes and sending them for biopsy, so those patients had other symptoms of lymphoma that triggered the need for a biopsy of suspicious lymph nodes.)