6 ms·

You're understating the costs. Determining whether something is (non) malignant isn't trivial. It often requires a more invasive test (e.g., biopsy, explorator

You're understating the costs. Determining whether something is (non) malignant isn't trivial. It often requires a more invasive test (e.g., biopsy, exploratory surgery). We try to avoid those procedures not just because we're cheap or afraid, but because they have a real risk of harming us 'squishy humans'. For example, detecting prostate cancer a few months earlier is often not a huge win on its own. It is even less of a success if doing so requires that four people have allergic reactions to the anesthetic and two others acquire some kind of infection at the biopsy site. It's certainly possible that more data would eventually let us avoid most invasive followups, that's nowhere near certain. Even if it were, the ethical calculus is still pretty tricky.

stcredzero 7y ago
You're understating the costs. I think you're correct in the current context. However, this strikes me as a sign of some kind of paradigm shift waiting to happen, enabled by the reduced cost of data gathering, data processing, and improvements in AI. There was a time when many things which are mass produced now were once handcrafted luxury items. Perhaps, as technology improves, it will one day be cost effective to take a whole body scan into account. I can imagine a day when an AI would digest the information from a full body scan, then autonomously plan robot keyhole surgery to take many of the biopsies. It's certainly possible that more data would eventually let us avoid most invasive followups, that's nowhere near certain. I think it's likely to happen in decades, if our civilization doesn't fall soon.
- saulrh 7y ago
  Perhaps, as technology improves, it will one day be cost effective to take a whole body scan into account. That's the really funny thing about this: A colossal library of full-body imaging studies over time is exactly the kind of technology that would make that library useable. Think about Google 411 and similar projects: Voice recognition was unusable until people dumped a ton of money into bootstrapping the necessary datasets and now I talk to my phone every day. Similarly, I bet that a bunch of that "anomalies are indistinguishable on images" is solely because we don't have enough images about non-malignant anomalies over time. The data itself would be the technology that makes it usable.
koboll 7y ago
It's nice that you think those are costs worth remaining ignorant over. However, when the ignorance is about things that literally might kill me, my personal opinion is that it's worth it.
- mattkrause 7y ago
  The word 'cost' seems to be confusing things. Both options have risks and both options can kill you. Namely: A) Doing nothing may allow a problem to fester until it either kills you or becomes detectable with standard treatments. However, you have no exposure whatsoever to side effects, infections, or medical errors for the things that are missed. B) Doing whole-body MRI 'fishing expeditions' decreases the risk of missing something, but increases the likelihood of possible false positives. Each thing flagged by the scan now needs to be ruled out (otherwise, why bother?) and this usually requires invasive procedures with their own risks. With our current imaging and understanding of biology, Option A may be less likely to kill people. Opinion doesn't even have to enter into this--you can literally run the numbers. It's worth noting that we limit testing FOR EVERYTHING. When you get a blood test, you could be screened for everything from ADH to Zika. You aren't though, because you're almost certainly a perfectly healthy outlier on a few tests; that's just how statistics work (someone has to be 3 sigma above the mean). Instead, tests are picked and interpreted based on your symptoms and circumstances.
  - agent008t 7y ago
    Speaking of blood tests - where does the uncertainty come in there? Is the measuring equipment noisy, so they might detect some marker when it is actually not present? Or is it that you can actually have a high concentration of whatever they are looking for in your blood but it somehow just be normal for you because you are an outlier? I tend to think it is the former but can anyone clarify?
    - mattkrause 7y ago
      Uncertainty is everywhere! The normative values aren't handed down from God, or some definite evidence of health. Instead, they were the typical range (mean ± 3SD, percentiles, etc) from a sample of healthy people, possibly matched for demographics (e.g., sex). Suppose we set each range so that it contains 99/100 healthy people. It would only take about 70 independent tests before you have a 50:50 chance of being outside that range on one of them--and that's assuming you're an exact match for the reference population. There's also error in the measurements themselves. Some of it is errors in the actual procedure or preparation: cross-contamination between samples, dust blows into the well, etc. However, many of the tests are stochastic too. Some measure binding between stuff in your blood (e.g., antibodies) and a "probe" that's designed to detect them. This usually works, but non-specific binding can cause false positives (the probe binds something that is similar to, but not quite the same as, the target). Other conditions can cause false negatives. The "front line" screenings are usually meant to be cheap, fast, and biased towards false positives. You might be interested in a fairly common statistics question about screening. Suppose you had a test that is 99% reliable: 99% of sick people test positive; 99% of healthy people test negative. The disease itself is somewhat rare--only 1% of people have it. If you test positive, what are the odds you're actually sick? The answer[0] will explain why we don't test or scan people for tons of rare diseases, even with very reliable (and free) tests. [0] ʎʇɟᴉɟ-ʎʇɟᴉɟ
Wowfunhappy 7y ago
> For example, detecting prostate cancer a few months earlier is often not a huge win on its own. It is even less of a success if doing so requires that four people have allergic reactions to the anesthetic and two others acquire some kind of infection at the biopsy site. Then the doctor should recommend not attempting that type of detection. I find it quite hard to believe that, in an ideal world (!), less data would actually be better. The doctor should still have the ability (at least in theory) to decide what information is worth investigating further, and what should be ignored.
- mattkrause 7y ago
  Sure, in the not-for-profit Vulcan medical system, this would might be grand. Even in our world I'd agree that in isolation, more information is always better. The issue is that this sort of information isn't free. The full body scan isn't free. Following up on it, which is the whole point, 'costs' increased risks of adverse outcomes (from biopsies), it 'costs' emotional anxiety, and it costs even more actual money. The argument is that right now, these whole body scans aren't worth the cost. You're more likely to find a few things you should ignore (but will probably worry over) and a few things you should follow up on (but will be benign). You're less likely to catch something deadly and just in the nick of time.
- cjensen 7y ago
  In the US system with malpractice lawsuits, there will be followup in most cases. US Doctors are still furious over the amount of unnecessary testing that occurred as a result of the "whole body scan at third party facility" fad from a decade or two ago.
  - Wowfunhappy 7y ago
    We should focus on the core problem, instead of "this device gives patients too much data."
    - cjensen 7y ago
      The core problem is there is zero evidence that a whole-body scan saves more lives than are lost due to the radiation of a whole-body scan.
Someone 7y ago
”Determining whether something is (non) malignant isn't trivial. It often requires a more invasive test (e.g., biopsy, exploratory surgery)” Not necessarily, waiting can in many cases tell you whether something is malignant. If we had, say, a century of monthly full-body MRIs of a million persons, together with their history and cause of death, the technology to align those scans across time, and the technology to analyze such a data set, a retrospective cohort study (https://en.wikipedia.org/wiki/Retrospective_cohort_study https://en.wikipedia.org/wiki/Retrospective_cohort_study) probably could uncover quite some interesting and useful information. If, at every step, you pick the option with the highest expected QALYs (https://en.wikipedia.org/wiki/Quality-adjusted_life_year https://en.wikipedia.org/wiki/Quality-adjusted_life_year), and you manage to make doing the MRI very efficient, I think doing that experiment even might pass an ethics committee (at the cost of making the analysis harder) (might because one could argue that the patient would be better of if the money spent doing those MRIs were spent on something else) Unfortunately, doing such an experiment isn’t practical (¿yet?).
- mattkrause 7y ago
  Two reasons I think this is not the way to go: First, the cost would be insane. A century of monthly MRIs is 1200 scans per person, or 1.2B scans to finish your hypothetical dataset. We pay about $US 550/hr for scanner time, using a research scanner that's subsidized (i.e., we're just covering costs, not making a profit). The article doesn't say how long the scan is. You can burn as much scanner time as you want chasing resolution/quality, but an hour seems reasonable. That comes out to $660B, which is...a lot, and we haven't even paid staff yet! Second, we have sorta tried this already. There's a massive neuroscience project to scan tons of brains called the Human Connectome Project. They have 1200 subjects, some scanned multiple times, behavioral measures, health outcomes, the works.... People have certainly found stuff in the data (I'm using some of it right now), but it hasn't lead to wild breakthroughs. There's a ongoing debate about whether this money would have been better spent on hypothesis-driven research instead.
  - briandear 7y ago
    At that scale, scans wouldn’t cost $550 per hour. “Because it’s too expensive,” seems like a great opportunity for some clever startup to figure out a way to make it less expensive. Computers used to take up entire rooms. Flying across the country used to be insanely expensive. Cell phones used to cost a ton of money per minute. Reducing the cost of scanning, or developing entirely new scanning tech isn’t science fiction, it’s the future.

stcredzero 7y ago

You're understating the costs. I think you're correct in the current context. However, this strikes me as a sign of some kind of paradigm shift waiting to happen, enabled by the reduced cost of data gathering, data processing, and improvements in AI. There was a time when many things which are mass produced now were once handcrafted luxury items. Perhaps, as technology improves, it will one day be cost effective to take a whole body scan into account. I can imagine a day when an AI would digest the information from a full body scan, then autonomously plan robot keyhole surgery to take many of the biopsies. It's certainly possible that more data would eventually let us avoid most invasive followups, that's nowhere near certain. I think it's likely to happen in decades, if our civilization doesn't fall soon.

saulrh 7y ago
Perhaps, as technology improves, it will one day be cost effective to take a whole body scan into account. That's the really funny thing about this: A colossal library of full-body imaging studies over time is exactly the kind of technology that would make that library useable. Think about Google 411 and similar projects: Voice recognition was unusable until people dumped a ton of money into bootstrapping the necessary datasets and now I talk to my phone every day. Similarly, I bet that a bunch of that "anomalies are indistinguishable on images" is solely because we don't have enough images about non-malignant anomalies over time. The data itself would be the technology that makes it usable.

koboll 7y ago

It's nice that you think those are costs worth remaining ignorant over. However, when the ignorance is about things that literally might kill me, my personal opinion is that it's worth it.

mattkrause 7y ago
The word 'cost' seems to be confusing things. Both options have risks and both options can kill you. Namely: A) Doing nothing may allow a problem to fester until it either kills you or becomes detectable with standard treatments. However, you have no exposure whatsoever to side effects, infections, or medical errors for the things that are missed. B) Doing whole-body MRI 'fishing expeditions' decreases the risk of missing something, but increases the likelihood of possible false positives. Each thing flagged by the scan now needs to be ruled out (otherwise, why bother?) and this usually requires invasive procedures with their own risks. With our current imaging and understanding of biology, Option A may be less likely to kill people. Opinion doesn't even have to enter into this--you can literally run the numbers. It's worth noting that we limit testing FOR EVERYTHING. When you get a blood test, you could be screened for everything from ADH to Zika. You aren't though, because you're almost certainly a perfectly healthy outlier on a few tests; that's just how statistics work (someone has to be 3 sigma above the mean). Instead, tests are picked and interpreted based on your symptoms and circumstances.
- agent008t 7y ago
  Speaking of blood tests - where does the uncertainty come in there? Is the measuring equipment noisy, so they might detect some marker when it is actually not present? Or is it that you can actually have a high concentration of whatever they are looking for in your blood but it somehow just be normal for you because you are an outlier? I tend to think it is the former but can anyone clarify?
  - mattkrause 7y ago
    Uncertainty is everywhere! The normative values aren't handed down from God, or some definite evidence of health. Instead, they were the typical range (mean ± 3SD, percentiles, etc) from a sample of healthy people, possibly matched for demographics (e.g., sex). Suppose we set each range so that it contains 99/100 healthy people. It would only take about 70 independent tests before you have a 50:50 chance of being outside that range on one of them--and that's assuming you're an exact match for the reference population. There's also error in the measurements themselves. Some of it is errors in the actual procedure or preparation: cross-contamination between samples, dust blows into the well, etc. However, many of the tests are stochastic too. Some measure binding between stuff in your blood (e.g., antibodies) and a "probe" that's designed to detect them. This usually works, but non-specific binding can cause false positives (the probe binds something that is similar to, but not quite the same as, the target). Other conditions can cause false negatives. The "front line" screenings are usually meant to be cheap, fast, and biased towards false positives. You might be interested in a fairly common statistics question about screening. Suppose you had a test that is 99% reliable: 99% of sick people test positive; 99% of healthy people test negative. The disease itself is somewhat rare--only 1% of people have it. If you test positive, what are the odds you're actually sick? The answer[0] will explain why we don't test or scan people for tons of rare diseases, even with very reliable (and free) tests. [0] ʎʇɟᴉɟ-ʎʇɟᴉɟ

Wowfunhappy 7y ago

> For example, detecting prostate cancer a few months earlier is often not a huge win on its own. It is even less of a success if doing so requires that four people have allergic reactions to the anesthetic and two others acquire some kind of infection at the biopsy site. Then the doctor should recommend not attempting that type of detection. I find it quite hard to believe that, in an ideal world (!), less data would actually be better. The doctor should still have the ability (at least in theory) to decide what information is worth investigating further, and what should be ignored.

mattkrause 7y ago
Sure, in the not-for-profit Vulcan medical system, this would might be grand. Even in our world I'd agree that in isolation, more information is always better. The issue is that this sort of information isn't free. The full body scan isn't free. Following up on it, which is the whole point, 'costs' increased risks of adverse outcomes (from biopsies), it 'costs' emotional anxiety, and it costs even more actual money. The argument is that right now, these whole body scans aren't worth the cost. You're more likely to find a few things you should ignore (but will probably worry over) and a few things you should follow up on (but will be benign). You're less likely to catch something deadly and just in the nick of time.
cjensen 7y ago
In the US system with malpractice lawsuits, there will be followup in most cases. US Doctors are still furious over the amount of unnecessary testing that occurred as a result of the "whole body scan at third party facility" fad from a decade or two ago.
- Wowfunhappy 7y ago
  We should focus on the core problem, instead of "this device gives patients too much data."
  - cjensen 7y ago
    The core problem is there is zero evidence that a whole-body scan saves more lives than are lost due to the radiation of a whole-body scan.

Someone 7y ago

”Determining whether something is (non) malignant isn't trivial. It often requires a more invasive test (e.g., biopsy, exploratory surgery)” Not necessarily, waiting can in many cases tell you whether something is malignant. If we had, say, a century of monthly full-body MRIs of a million persons, together with their history and cause of death, the technology to align those scans across time, and the technology to analyze such a data set, a retrospective cohort study (https://en.wikipedia.org/wiki/Retrospective_cohort_study https://en.wikipedia.org/wiki/Retrospective_cohort_study) probably could uncover quite some interesting and useful information. If, at every step, you pick the option with the highest expected QALYs (https://en.wikipedia.org/wiki/Quality-adjusted_life_year https://en.wikipedia.org/wiki/Quality-adjusted_life_year), and you manage to make doing the MRI very efficient, I think doing that experiment even might pass an ethics committee (at the cost of making the analysis harder) (might because one could argue that the patient would be better of if the money spent doing those MRIs were spent on something else) Unfortunately, doing such an experiment isn’t practical (¿yet?).

mattkrause 7y ago
Two reasons I think this is not the way to go: First, the cost would be insane. A century of monthly MRIs is 1200 scans per person, or 1.2B scans to finish your hypothetical dataset. We pay about $US 550/hr for scanner time, using a research scanner that's subsidized (i.e., we're just covering costs, not making a profit). The article doesn't say how long the scan is. You can burn as much scanner time as you want chasing resolution/quality, but an hour seems reasonable. That comes out to $660B, which is...a lot, and we haven't even paid staff yet! Second, we have sorta tried this already. There's a massive neuroscience project to scan tons of brains called the Human Connectome Project. They have 1200 subjects, some scanned multiple times, behavioral measures, health outcomes, the works.... People have certainly found stuff in the data (I'm using some of it right now), but it hasn't lead to wild breakthroughs. There's a ongoing debate about whether this money would have been better spent on hypothesis-driven research instead.
- briandear 7y ago
  At that scale, scans wouldn’t cost $550 per hour. “Because it’s too expensive,” seems like a great opportunity for some clever startup to figure out a way to make it less expensive. Computers used to take up entire rooms. Flying across the country used to be insanely expensive. Cell phones used to cost a ton of money per minute. Reducing the cost of scanning, or developing entirely new scanning tech isn’t science fiction, it’s the future.