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Doctors here are cognitively captured by a system designed to limit cost (and that's mostly a good thing) But scanning frequently is overwhelmingly good for th

Doctors here are cognitively captured by a system designed to limit cost (and that's mostly a good thing) But scanning frequently is overwhelmingly good for the patient. The problem is the doctors. Imagine two possibilities. 1. You scan every six months and a doctor reviews your scans but never tells you anything no matter what 2. You scan every six months and a doctor reviews your scans and only tells you results if you have an obviously growing mass that has a probability greater than 95% of being cancerous Obviously #2 is better for the patient than #1, but #1 is equivalent to never testing if you ignore cost. So the actual reason we don't have effect frequent scans combined with effective diagnostic techniques is cost, and doctors cope with this reality by saying clearly wrong things about "over diagnosis". It's a local minimum of the payer/provider dynamic that has nothing to do with scans per se.

lich_king 8mo ago
Why is it good for the patient? I think that to claim this, you'd need to show a difference in outcomes. Here, you have a tool with a ~100% false positive rate, so if we start administering it to everyone, it will almost certainly cost lives. Botched biopsies, unnecessary treatments, other complications. Not to mention the huge cost that would divert money from other welfare programs. So you need to show that when it actually detects something, it saves at least as many lives. And I doubt that's the case.
- mgraczyk 8mo ago
  Did you read my two options? Do you agree option 2 is better than option 1? If so, then scans are better than no scan You don't need to show that it's possible to avoid false positives. That's doctors being irrational. You only need to show that it's possible to build a diagnostic system that's better than no testing, and I have shown that already
  - lich_king 8mo ago
    No. To argue for the benefit of the procedure, you need to show a difference in outcomes. Not that it can detect something, even if it could (which whole-body MRIs clearly don't). That the detection improves your chances of survival. If you have an growing mass in your body, then if it's cancer, after a year, it might be too late for treatment. Or it may turn out to be nothing: a benign tumor / cyst / fat deposit in an unusual place. Or it may be slow-growing prostate cancer that you can live with for another 20 years, and maybe it's the chemotherapy that will do you in. It's really not that clear-cut in medicine. To give you have another example: let's say that the risk of appendicitis in people who have an appendix is 1%. And the risk in people who had an appendix removed is 0%. Does this justify proactively removing the appendix? No, because the consequences of complications are much higher than the harm you're preventing. The same applies here: detection, even if 100% accurate, doesn't mean anything. You need to show that what you do with the result actually helps.
    - mgraczyk 8mo ago
      The difference in out come is With my change: 95% of people who are shown scans have cancer and are treated earlier. 5% of people do not have cancer and get CT scans. 0.5% of people get useless biopsies Without my change: many of those 95% die, the 0.5% do not get useless biopsies And the beauty of this is you can pick the percentage! > If you have an growing mass in your body, then after a year, it may very well no longer make a difference whether you treat it or not. Or it may be that you would have lived another 20 years just fine This is just wrong for many parts of the body. In your brain? Your lungs? Growing for a year between 3 scans 6 months apart? Extremely unlikely to be benign > The same applies here: detection, even if 100% accurate, doesn't mean anything. You need to show that what you do with the result actually helps. This is wrong. If you had a 100% accurate cancer detector, fewer people would die of cancer with no downside
      - deleted 8mo ago
        [deleted]
      - alexey-salmin 8mo ago
        > With my change: 95% of people who are shown scans have cancer and are treated earlier. 5% of people do not have cancer and get CT scans. 0.5% of people get useless biopsies Without my change: many of those 95% die, the 0.5% do not get useless biopsies You assume that treating cancer automatically improves the outcome. Treating cancer often kills you, so treating a non-fatal tumor can easily be a bad decision. And a lot of the tumors found by agressive scans are like that, but we don't know yet how much exactly and how to tell one from the other. It's a new question that requires decades-long observations to answer. > This is wrong. If you had a 100% accurate cancer detector, fewer people would die of cancer with no downside You're saying it as if detection somehow cures cancer, it doesn't.
        mgraczyk 8mo ago
        > You're saying it as if detection somehow cures cancer, it doesn't. No, I didn't say the detector would cause cancer to be cured. I said fewer people would die with no downsides. If treatment is sometimes harmful then the detector also fixes that, you'd never treat people without cancer
- jml78 8mo ago
  I wouldn't argue we should roll this out to everyone. But I am glad it exists. I commented earlier in this topic about how it caught cancer in my wife at the age of 44. She didn't have to go through chemo or radiation treatment because it was caught so early. Surgery removed the whole cancer. Additionally for me, I have a scan that shows what my body currently has. I had something show up that I did get a scope to check out that was a pancreatic rest. No big deal. Now, if I ever have another MRI and somethings is somewhere else, we have a baseline to compare against. Everything is a risk calculation. When I did my MRI, I also had other procedures done like a heart calcium score. I will get a little more personal. We didn't do it out of the blue. My wife and I decided we want to live on a sailboat. That was a big purchase for us and boats take a long time to sell. We didn't want to commit to such a purchase then 1 year later find out either of us had cancer then we have the stress of cancer and the stress of trying to sell a boat. I would never suggest everyone do it, but I am happy we did.
- MagicMoonlight 8mo ago
  You are deep in the cope here. There is no world in which biopsies cause more harm than detecting every cancer at stage 1 prevents. > Not to mention the huge cost that would divert money from shareholders Ah, that explains it
  - dogmatism 8mo ago
    I’ll give you a counter example. I had an MRI of my neck for unrelated reasons. It found a thyroid nodule with suspicious characteristics. Incidentally I had had an MRI of the same areaa few years before and it wasn’t there. So I had a biopsy. Which was equivocal also. So I had it out which involved removing half my thyroid. Turns out it was a cancer but like the least serious kind, in fact the classification of it as actual cancer has gone back and forth over the years But my other half of my thyroid couldn’t produce enough thyroid hormone, and now I have to take thyroid replacement the rest of my life to start alive Also the surgery affected my voice and I sound like RFK jr now. I clearly suffered some harm, and even after having the thing out, it’s unclear if that was beneficial at all. A large proportion of these kind of tumors quit growing and never do anything bad. But some do. So who knows. Was the tradeoff worth it? I don’t think it’s possible to say
skywalqer 8mo ago
Best comment here
somewhereoutth 8mo ago
No. When there is low prevalence of a condition, but a non-zero false positive rate of a test, the false positives generated by universal testing can in fact be a net dis-benefit (worry, invasive further procedures, etc) to the patient population as a whole, regardless of cost. This is a well understood statistical phenomenon, and is carefully considered by healthcare systems when advising on testing.
- mgraczyk 8mo ago
  Read my #2 option, which accounts for that
  - lucianbr 8mo ago
    As if there was an easy, foolproof and precise way to calculate these probabilities. "Just only alter the patient when it is appropriate" he said. You can solve all the world's problems this way, just "always do the right thing". Reality, unfortunately, is more complicated. What if in reality the doctors can only say if the probability is above 60% or not? What if some doctors are better than others at estimating probabilities? What if estimates are influenced by financial reasons by some entity like the hospital or insurer?
    - mgraczyk 8mo ago
      > What if estimates are influenced by financial reasons by some entity like the hospital or insurer? It's this one It doesn't matter that some cancers are hard to diagnose. What matters is that some are not hard, especially if you have multiple scans spanning several years Did you know optometrists now scan your retina during ordinary eyeglasses appointments? They didn't do this in the past because it was too expensive. But optometrists cannot diagnose or treat based on these scans. They refer you to an opthamologist. Some day your PCP will do the same with MRIs, but only once they are cheap. For now only rich people have this luxury
deleted 8mo ago
[deleted]
RataNova 8mo ago
I don't think this is doctors being captured by the system so much as medicine being cautious about scaling interventions without strong outcome data
- amanaplanacanal 8mo ago
  "First, do no harm."
- mgraczyk 8mo ago
  Nope, this is cope Tons of diagnostic interventions have been scaled without strong outcome data. For example many clinics now do fractional exhaled nitric oxide (FeNO) tests because they are safe, fairly cheap, and patients often pay directly out of pocket so they are easy to make money on. But the evidence for the diagnostic usefulness of this test is extremely low, multiple meta analysis have concluded. The reason FeNO tests are done but not MRIs is because FeNO tests are $40
sethev 8mo ago
Your case #2 doesn't have nearly enough information to say whether it's obviously better for a population of patients. There are a lot of other variables you would need to know: - The accuracy of detecting a mass - The true distribution of masses in the population - The likelihood that of falsely detecting a mass in the same place twice (you seem to implicitly assume that false detections are uncorrelated with each other) - The likelihood that a real mass is cancerous (you stipulate that this is 95% in your scenario, but you don't say what other factors are used to determine this - as opposed to just knowing that there's a mass that grew.) - The positive effect of treatment in the case of true-positives. - The negative effect of treatment or further diagnostics in the case of false-positive. Saying that doctors are lying about over diagnosis to cope with the fact that diagnostic techniques are too expensive is absurd. They have to actually make decisions in the real world, where your two neat little categories can't be known even if they hypothetically exist.

lich_king 8mo ago

Why is it good for the patient? I think that to claim this, you'd need to show a difference in outcomes. Here, you have a tool with a ~100% false positive rate, so if we start administering it to everyone, it will almost certainly cost lives. Botched biopsies, unnecessary treatments, other complications. Not to mention the huge cost that would divert money from other welfare programs. So you need to show that when it actually detects something, it saves at least as many lives. And I doubt that's the case.

mgraczyk 8mo ago
Did you read my two options? Do you agree option 2 is better than option 1? If so, then scans are better than no scan You don't need to show that it's possible to avoid false positives. That's doctors being irrational. You only need to show that it's possible to build a diagnostic system that's better than no testing, and I have shown that already
- lich_king 8mo ago
  No. To argue for the benefit of the procedure, you need to show a difference in outcomes. Not that it can detect something, even if it could (which whole-body MRIs clearly don't). That the detection improves your chances of survival. If you have an growing mass in your body, then if it's cancer, after a year, it might be too late for treatment. Or it may turn out to be nothing: a benign tumor / cyst / fat deposit in an unusual place. Or it may be slow-growing prostate cancer that you can live with for another 20 years, and maybe it's the chemotherapy that will do you in. It's really not that clear-cut in medicine. To give you have another example: let's say that the risk of appendicitis in people who have an appendix is 1%. And the risk in people who had an appendix removed is 0%. Does this justify proactively removing the appendix? No, because the consequences of complications are much higher than the harm you're preventing. The same applies here: detection, even if 100% accurate, doesn't mean anything. You need to show that what you do with the result actually helps.
  - mgraczyk 8mo ago
    The difference in out come is With my change: 95% of people who are shown scans have cancer and are treated earlier. 5% of people do not have cancer and get CT scans. 0.5% of people get useless biopsies Without my change: many of those 95% die, the 0.5% do not get useless biopsies And the beauty of this is you can pick the percentage! > If you have an growing mass in your body, then after a year, it may very well no longer make a difference whether you treat it or not. Or it may be that you would have lived another 20 years just fine This is just wrong for many parts of the body. In your brain? Your lungs? Growing for a year between 3 scans 6 months apart? Extremely unlikely to be benign > The same applies here: detection, even if 100% accurate, doesn't mean anything. You need to show that what you do with the result actually helps. This is wrong. If you had a 100% accurate cancer detector, fewer people would die of cancer with no downside
    - deleted 8mo ago
      [deleted]
    - alexey-salmin 8mo ago
      > With my change: 95% of people who are shown scans have cancer and are treated earlier. 5% of people do not have cancer and get CT scans. 0.5% of people get useless biopsies Without my change: many of those 95% die, the 0.5% do not get useless biopsies You assume that treating cancer automatically improves the outcome. Treating cancer often kills you, so treating a non-fatal tumor can easily be a bad decision. And a lot of the tumors found by agressive scans are like that, but we don't know yet how much exactly and how to tell one from the other. It's a new question that requires decades-long observations to answer. > This is wrong. If you had a 100% accurate cancer detector, fewer people would die of cancer with no downside You're saying it as if detection somehow cures cancer, it doesn't.
      - mgraczyk 8mo ago
        > You're saying it as if detection somehow cures cancer, it doesn't. No, I didn't say the detector would cause cancer to be cured. I said fewer people would die with no downsides. If treatment is sometimes harmful then the detector also fixes that, you'd never treat people without cancer
jml78 8mo ago
I wouldn't argue we should roll this out to everyone. But I am glad it exists. I commented earlier in this topic about how it caught cancer in my wife at the age of 44. She didn't have to go through chemo or radiation treatment because it was caught so early. Surgery removed the whole cancer. Additionally for me, I have a scan that shows what my body currently has. I had something show up that I did get a scope to check out that was a pancreatic rest. No big deal. Now, if I ever have another MRI and somethings is somewhere else, we have a baseline to compare against. Everything is a risk calculation. When I did my MRI, I also had other procedures done like a heart calcium score. I will get a little more personal. We didn't do it out of the blue. My wife and I decided we want to live on a sailboat. That was a big purchase for us and boats take a long time to sell. We didn't want to commit to such a purchase then 1 year later find out either of us had cancer then we have the stress of cancer and the stress of trying to sell a boat. I would never suggest everyone do it, but I am happy we did.
MagicMoonlight 8mo ago
You are deep in the cope here. There is no world in which biopsies cause more harm than detecting every cancer at stage 1 prevents. > Not to mention the huge cost that would divert money from shareholders Ah, that explains it
- dogmatism 8mo ago
  I’ll give you a counter example. I had an MRI of my neck for unrelated reasons. It found a thyroid nodule with suspicious characteristics. Incidentally I had had an MRI of the same areaa few years before and it wasn’t there. So I had a biopsy. Which was equivocal also. So I had it out which involved removing half my thyroid. Turns out it was a cancer but like the least serious kind, in fact the classification of it as actual cancer has gone back and forth over the years But my other half of my thyroid couldn’t produce enough thyroid hormone, and now I have to take thyroid replacement the rest of my life to start alive Also the surgery affected my voice and I sound like RFK jr now. I clearly suffered some harm, and even after having the thing out, it’s unclear if that was beneficial at all. A large proportion of these kind of tumors quit growing and never do anything bad. But some do. So who knows. Was the tradeoff worth it? I don’t think it’s possible to say

skywalqer 8mo ago

Best comment here

somewhereoutth 8mo ago

No. When there is low prevalence of a condition, but a non-zero false positive rate of a test, the false positives generated by universal testing can in fact be a net dis-benefit (worry, invasive further procedures, etc) to the patient population as a whole, regardless of cost. This is a well understood statistical phenomenon, and is carefully considered by healthcare systems when advising on testing.

mgraczyk 8mo ago
Read my #2 option, which accounts for that
- lucianbr 8mo ago
  As if there was an easy, foolproof and precise way to calculate these probabilities. "Just only alter the patient when it is appropriate" he said. You can solve all the world's problems this way, just "always do the right thing". Reality, unfortunately, is more complicated. What if in reality the doctors can only say if the probability is above 60% or not? What if some doctors are better than others at estimating probabilities? What if estimates are influenced by financial reasons by some entity like the hospital or insurer?
  - mgraczyk 8mo ago
    > What if estimates are influenced by financial reasons by some entity like the hospital or insurer? It's this one It doesn't matter that some cancers are hard to diagnose. What matters is that some are not hard, especially if you have multiple scans spanning several years Did you know optometrists now scan your retina during ordinary eyeglasses appointments? They didn't do this in the past because it was too expensive. But optometrists cannot diagnose or treat based on these scans. They refer you to an opthamologist. Some day your PCP will do the same with MRIs, but only once they are cheap. For now only rich people have this luxury

deleted 8mo ago

[deleted]

RataNova 8mo ago

I don't think this is doctors being captured by the system so much as medicine being cautious about scaling interventions without strong outcome data

amanaplanacanal 8mo ago
"First, do no harm."
mgraczyk 8mo ago
Nope, this is cope Tons of diagnostic interventions have been scaled without strong outcome data. For example many clinics now do fractional exhaled nitric oxide (FeNO) tests because they are safe, fairly cheap, and patients often pay directly out of pocket so they are easy to make money on. But the evidence for the diagnostic usefulness of this test is extremely low, multiple meta analysis have concluded. The reason FeNO tests are done but not MRIs is because FeNO tests are $40

sethev 8mo ago

Your case #2 doesn't have nearly enough information to say whether it's obviously better for a population of patients. There are a lot of other variables you would need to know: - The accuracy of detecting a mass - The true distribution of masses in the population - The likelihood that of falsely detecting a mass in the same place twice (you seem to implicitly assume that false detections are uncorrelated with each other) - The likelihood that a real mass is cancerous (you stipulate that this is 95% in your scenario, but you don't say what other factors are used to determine this - as opposed to just knowing that there's a mass that grew.) - The positive effect of treatment in the case of true-positives. - The negative effect of treatment or further diagnostics in the case of false-positive. Saying that doctors are lying about over diagnosis to cope with the fact that diagnostic techniques are too expensive is absurd. They have to actually make decisions in the real world, where your two neat little categories can't be known even if they hypothetically exist.