11 ms·

Actually you don't want this, and you are describing a nightmare scenario that everyone who studies health policy understands all too well. Mass screening of he

Actually you don't want this, and you are describing a nightmare scenario that everyone who studies health policy understands all too well. Mass screening of healthy people will result in extreme iatrogenics and unnecessary psychological damage and stress (which leads to physical effects as well), not to mention overwhelming the medical system. The fact is that many things that could be detected will never result in symptoms or other noticeable problems. Further, for many things that can be detected we can't really do much about, so by detecting it early you are just reducing the amount of life they have left without worrying about their disease, or causing unnecessary treatment (which includes unnecessary damage, cost, stress, etc.)

throwawaynotmd 5y ago
The argument you’re making has always bothered me because it’s hiding the ball. If finding something that otherwise carries no symptoms is best left untreated, then the fact that you found it should make no difference to the decision. The doctor should say that the best course of action is to do nothing. More information can never be harmful. If you know information is best not acted on in the abstract, then you also know you should not act on it in particular. So what you really mean but have left unspoken is one of two things. First, that doctors are untrustworthy people who make recommendations and decisions based on concerns other than their patient’s wellbeing, such as covering their asses from lawsuits or making more money. But rather than fix that, you would rather keep patients more ignorant and away from the doctor in the first place. Which actively harms people who do have honest doctors. That is, your approach of not testing hurts people with honest doctors to protect people with dishonest doctors. Or second, if you take dumb patients as the problem, you are willing to hurt people with good decision making ability (who would heed their good doctor’s advice to leave the possible ailment untreated) so you can protect people with bad decision making. Because many times, these tests will uncover things that obviously need treatment. They will save many lives. But because more stupid people will hurt themselves, then no one should have access to them. The political and moral assumptions built into these positions are immense and yet the medical field tucks those away and pretends that this is just a purely scientific truth, that someone running more harmless tests is actually inherently harmful. That is a lie! And a very nasty one at that.
- ArtRichards 5y ago
  If thats how you feel, I invite you to slapsgiving this year! Exactly 18:32 on the eve of Thanksgiving.
- TaupeRanger 5y ago
  Lots of problematic assumptions in your reply. >If finding something that otherwise carries no symptoms is best left untreated, then the fact that you found it should make no difference to the decision. The doctor should say that the best course of action is to do nothing. More information can never be harmful. Absolutely and demonstratively false. There is an entire field of health policy that destroys this harmful idea. First of all, just because something doesn't carry symptoms NOW doesn't mean it won't carry symptoms LATER, but doctors can't always predict this and aren't perfect decision making machines. Many times the patient will push them for further tests and treatment (or the doctors will advocate for it to ease the mind of the patient) which leads to potential harm from unnecessary treatments. And this is just ONE of the ways patients are harmed by unnecessary screening. There is also the psychological damage of having a condition you wouldn't have otherwise known about, and living with that knowledge (take aneurysms for example). Psychological stress has a real physical toll on the body. Then there's the COST associated with unnecessary screening and treatments, which (especially in the US) can run into the thousands quite easily for even simple interventions as a result of unnecessary screening. Even after that, a screening process can also find something that could be bad, but in some patients doesn't actually decrease their lifespan or quality of life. If we have no way of adjudicating between these cases or predicting which cases will end up bad if left untreated at the present moment, what do you think will happen? People will ask to be treated anyway, and iatrogenics will rear its ugly head. You cannot ASSUME that screening is automatically good. It must PROVE itself as such in a randomized clinical trial. This trial must show that people live longer and/or better as a result of this intervention. In many well documented cases, this turns out NOT to be the case, which entirely destroys your original rebuttal.
  - throwawaynotmd 5y ago
    >Many times the patient will push them for further tests and treatment (or the doctors will advocate for it to ease the mind of the patient) which leads to potential harm from unnecessary treatments. >People will ask to be treated anyway, and iatrogenics will rear its ugly head. I just want to say that you are in agreement with my position here. Your point about psychological problems is interesting, but as long as people know what they’re signing up for, it’s okay. Some people aren’t prone to anxiety. Why should they pay the price because other people are? Part of my original point was that implicit in your argument is that people capable of handling it should be denied something because more people incapable of handling it can’t be stopped from hurting themselves. I think many people do not agree with that moral reasoning, so medical people hide it behind objective looking statistics. And as for cost, I don’t take any arguments from medical people about cost seriously. The reason why costs are so high is because doctors and the medical field as a whole run a massive protectionist racket to keep the supply of medical professionals low. How fresh of them to say that because they’ve limited the supply of medical resources to enrich themselves, patients must pay by having less access to care.
BurningFrog 5y ago
Iatrogenics is when a treatment causes more harm than benefit.
plank_time 5y ago
Utterly wrong. You are conflating current technology like MRIs and CT scans that only detect lumps, to blood tests that detect CANCER. Yes, if every lump were treated and excised then it would be problematic. But CANCER is different. The only cancer that you might be able to leave alone is prostate because it grows so slowly. Everything else is a risk. And if we can treat cancer at early stage 1, then maybe people won’t be as afraid of it because it has such a high rate of cure. We don’t know that until we do it.
- TaupeRanger 5y ago
  You say "utterly wrong" and yet you clearly have no idea what you're talking about and have never even approached the field of health policy. Screening has to PROVE that it makes people live longer or better, just like any other intervention. It is not the case that screening is automatically good, otherwise we would be giving 20 year olds colonoscopies. Just because you find something, doesn't mean you've helped the patient, as anyone with a modicum of understanding in this field knows. Read this and learn something: https://www.bmj.com/content/352/bmj.h6080 https://www.bmj.com/content/352/bmj.h6080
  - plank_time 5y ago
    We don’t give colonoscopies to 20 years olds because it’s an expensive, invasive test with a low rate of cancer. We don’t give mammograms to under 40 year olds these days because the same and it’s notoriously inaccurate. We give blood glucose level tests and cholesterol tests to everyone every year at the physical because they are cheap and easy to administer. Even though the effects of both may take decades to have any effect and have no correlation to ultimate death. It’s about trade off of cost and convenience. If you detect pancreatic or colon cancer in a 20 year old patient via $1 blood test, that is immediately actionable. Cancer is ALWAYS actionable unless you’re talking about prostrate which grows slowly. But even in a 20 year old, you would want to treat that but maybe not a 70 year old. And we’ve never had the ability to detect stage 1 cancer of the deadliest types of cancer. Imagine the new treatments that might save lives if we could. Honestly, the number of people here who think they know better and citing unrelated research is bordering on anti-maskers parroting the surgeon general saying masks don’t work when they do.
Silhouette 5y ago
Mass screening of healthy people will result in ... But you don't know they're healthy. They might be sick but (so far) asymptomatic. That's why you screen, if you have a sufficiently accurate test available and you can make a useful intervention if the test gives a positive result. If we applied your argument consistently, we would abolish all cancer screening programmes, resulting in many extra deaths because early detection and treatment didn't happen. We'd stop checking up on heart health as people age, resulting in many extra deaths because people continued to live unhealthy lifestyles without realising what it was doing to them. We wouldn't be using rapid testing for COVID-19 to detect and isolate probable asymptomatic carriers who might spread the virus to others who wouldn't be so lucky. The list goes on. Good screening programmes save lives. It's as simple as that.
fallingknife 5y ago
I think it has more to do with how the kind of data collected from those mass screenings could be used to build predictive disease models that would put a lot of the guys making >= $300K to do a very poor job of keeping people healthy out of business.
treeman79 5y ago
I had a mystery illness. Spent hundreds of thousands on Er visits only to find it’s was a pair of fairly common conditions acting together. Blood work tests exists for both. A deep round of blood testing would have saved everyone a lot of time and money and suffering. Or I could have waited many years until the organ damage was so extensive that diagnosing was easier. Oh wait, that’s what ended up happening.
daemonk 5y ago
I understand this argument. But if we separate out the mass screening/data-collection approach from its practical constraints (undue stress, overwhelm medical system), I think we can both at least agree that it is a correct direction to head towards? Or is the status-quo already as well optimized as it could be?
iNane9000 5y ago
As it stands wealthy people can and do find more thorough medical treatment, including more frequent and exhaustive imaging, labs, etc... The conventional wisdom you cite only applies to those who can’t seek endless second opinions from specialists. There are many conditions that exist and are treatable in wealthier societies. The poor suffer those same afflictions but are untreated or misdiagnosed.
AlexCoventry 5y ago
If we optimistically assume the claimed 0.5% false positive rate is accurate, and all of the US got tested annually, that's 1.64M false positives per year. Cancer.gov is telling me that approximately 1.8M USians were expected to get cancer last year. That's a positive predictive value of 52%. That still seems highly informative, to me; much higher than the PPV for mammography according to this (admittedly old) study: [1]. Assuming the 0.5% FP rate holds (again, I know that's optimistic), would you still regard universal testing with this method to be harmful? [1] https://jamanetwork.com/journals/jama/article-abstract/409356 https://jamanetwork.com/journals/jama/article-abstract/40935...
- TaupeRanger 5y ago
  Good question. The proof is in the pudding. Run a well powered RCT and if the intervention helps patients live longer and/or better, then we should consider using it! It will be hard to design a study that includes all possible detected cancers, but there are ways around this - perhaps we begin by studying those cancers that are most common and lethal, and go from there.
- amelius 5y ago
  Isn't this exactly why the headline reads "blood test good enough to be rolled out"? I.e., higher FP rate, and it wouldn't be rolled out.
  - AlexCoventry 5y ago
    IIRC, the actual article says they're going to do a large trial, with 150k people, and someone in the article expresses skepticism that the estimated FP rate of 0.5% is accurate, because so far it was tested in people where there's some evidence of cancer.
- dan-robertson 5y ago
  Is that actually good though? It feels to me that there’s a big difference between explaining the implications of a positive result to someone who understands bayes theorem and someone who doesn’t. Another aspect of cancer screening is that detecting cancer earlier can improve key statistics like 5 year survival without affecting the actual disease in any way. Which can make screening sound more effective than it is.
handmodel 5y ago
I'm not sure. I weight myself everyday. Some people tell me not to do that but its honestly pretty good at keeping me in check and because I weigh myself everyday I know that sometimes I just get super bloated and put on four pounds of water and it will be gone in a couple days. When you get more data you learn to adjust how you interpret it and make better decisions. Likewise, if getting a false result 50% of the time becomes common (this assumes we never improve the tests) then people will know to adjust their priors. After all - I've had to go to specialists a few times for extra tests. I wouldn't say we ban those.
- shard 5y ago
  Yes. I meticulously tracked every calorie I ate for several months. Now I know how much of different types of food is how many calories, how many calories I eat per day, and most importantly what my different hunger levels mean in terms of the number of calories ingested. Combined with my weight tracking, which tells me my set weight / weight variance over a day or several days / food intake to gain or lose a certain amount of weight, I can easily control portions to hit my weight goals without thinking about it. I would imagine more health data would allow me to optimize in this fashion as well. If I can correlate health markers to my lifestyle often and directly, I can make better and more informed choices. Advocating against easy access to health data because some people can misuse it is the same kind of nanny state thinking that says encryption shouldn't be available to the masses because criminal enterprises can use it to hide their activities.
theptip 5y ago
While I agree with the point that you're making around employing caution against iatrogenics (with colonoscopies being a very good case study that one should make sure to understand before forming an opinion here, as you referenced in another point), I think you're overconfident in your prediction that this hypothetical scenario would be bad. I think your claim (based on sibling posts) is that in the current medical system, if we just added more screening, we'd not necessarily get net benefits. But I think that ignores the fact that, if we had cheap and high-resolution screening, we could fundamentally restructure many aspects of medical care. The BMJ article you linked in a sibling[1] notes that cancer screening may reduce cancer mortality but increase all-cause mortality. That's an unexpected and problematic result of getting referred to a cancer specialist that might not have (or be incentivized to care about) a wholistic picture of health when you screen positively for cancer. But if we had higher-resolution data, and conceptualized medicine as primarily preventive instead of curative, then it seems likely to me that overall mortality would be your target, we'd have richer data to be able to track that endpoint, and so we'd be more likely to catch the cases where an intervention caused unexpected harms (because we'd be tracking more indicators). In other words, the problem you're observing is that adding a bit more data to the current system can produce negative outcomes. But that problem would be fixed by adding even more data. (With the remaining question being, how much data would we need to add to reach the "net positive" regime?) I think you're arguing against a change that looks like a harm from the perspective of a local optimum that we're currently working towards, without considering the dramatic paradigm shift into another higher-utility region that would have been brought along by this sort of technology. In summary, I am much more optimistic that if we had orders of magnitude more data, we'd make better decisions, not worse. But I agree with your caution that it's not as easy as it seems. [1]: https://www.bmj.com/content/352/bmj.h6080 https://www.bmj.com/content/352/bmj.h6080
fierro 5y ago
this is a paternalistic point of view. People should be entitled to accumulate data about their own body -- any "negative" ramifications of this are personal problems.
soheil 5y ago
I wonder if the equivalent of extreme iatrogenics and unnecessary psychological damage and stress also occurs when monitoring servers too much. I have a feeling it does. This is why I typically set higher thresholds like more disk space, memory (equivalent of exercise and healthy diet?) that I really need so I stop monitoring my servers religiously.
LightMachine 5y ago
This mindset kills more people than Hitler. Have a good day.
lhorie 5y ago
I think you're casting too wide of a net there. Just because you've detected something early doesn't mean you automatically need aggressive interventions like chemotherapy. The impact might just end up being a line in your medical record for the family physician to keep an eye on during yearly routine exams. Breast cancer awareness programs are a good example of early screening programs not being an exercise in mass hysteria. Some early symptoms for eye conditions only require periodic observation up until it actually becomes a problem. Etc. Perhaps it is true - in the US, anyways - that there's a tendency to overly prescribe more aggressive interventions (read: more expensive ones), but my understanding is that the US model is the exception, not the rule, when looking at the rest of the world.
- vharuck 5y ago
  >Breast cancer awareness programs are a good example of early screening programs not being an exercise in mass hysteria. This example also shows how screening can be recommended against because that's better for public health. The US Preventive Services Task Force (indirectly decides what Medicaid/Medicare covers) has different recommendations than the American Cancer Society for how often women of certain ages should have mammograms. USPSTF recommends against routine mammograms for women aged 40 to 49 if they don't have other risk factors. ACS recommends biannual mammograms start at age 45. The reason they differ is because of how they weigh the reduction in deaths against the harm of false positives. Routine mammograms will prevent breast cancer death, no doubt about it. But notice neither recommends routine mammograms for all women below 45, even though they accounted for over 10% of breast cancer diagnoses in 2014-2018[0]. The math is tricky when comparing a risk of death against quality of life and economic costs. Public health is a matter of public policy as much as health. [0] https://seer.cancer.gov/statfacts/html/breast.html https://seer.cancer.gov/statfacts/html/breast.html
- throwawayboise 5y ago
  "The impact might just end up being a line in your medical record for the family physician to keep an eye on during yearly routine exams." And something to be on the back of your mind as a worry forever. I'd rather not know.
Buttons840 5y ago
> so by detecting it early you are just reducing the amount of life they have left without worrying about their disease I wonder if people would rather continue to live care free, spending most of their waking hours commuting and at work, or if they'd rather learn the truth and face the harsh reality that their time is about up and adjust their priorities accordingly?
- throwawayboise 5y ago
  Nobody knows when his time is up. You could be hit by a truck on your commute to work. I would rather live my life as it comes, for whatever length of time fate has given me.
captainmuon 5y ago
If you leave the treatment criteria the same, then yes, you are absolutely right. But you have to adjust those, too. Just a made-up example: Let's say someone has an advanced test for cancer run, and it comes back positive. You know from studies that treating people the same way as before with the advanced test leads to worse outcomes because of unneccessary treatment etc.. So what you could do is you do the simpler test afterwards. If it comes back negative, you don't treat -> you are in the same situation as before, only you can be more vigilant in future and see if the cancer grows. If the simpler test also comes back positive, you do the treatment. It's all about getting data (statistical and otherwise) on what the best treatment is, and acting on that.
nyokodo 5y ago
> Actually you don't want this, and you are describing a nightmare scenario that everyone who studies health policy understands all too well. Would a very large representative sample of volunteers doing this kind of hitherto unprecedented level of medical monitoring help improve this technology while limiting the unintended consequences? If we could get to the point where the technology was very highly predictive of specific outcomes and even had the ability to test early interventions on those outcomes, that would both allay the psychological cost of a population-wide roll-out and drastically improve outcomes across the board, would it not?

throwawaynotmd 5y ago

The argument you’re making has always bothered me because it’s hiding the ball. If finding something that otherwise carries no symptoms is best left untreated, then the fact that you found it should make no difference to the decision. The doctor should say that the best course of action is to do nothing. More information can never be harmful. If you know information is best not acted on in the abstract, then you also know you should not act on it in particular. So what you really mean but have left unspoken is one of two things. First, that doctors are untrustworthy people who make recommendations and decisions based on concerns other than their patient’s wellbeing, such as covering their asses from lawsuits or making more money. But rather than fix that, you would rather keep patients more ignorant and away from the doctor in the first place. Which actively harms people who do have honest doctors. That is, your approach of not testing hurts people with honest doctors to protect people with dishonest doctors. Or second, if you take dumb patients as the problem, you are willing to hurt people with good decision making ability (who would heed their good doctor’s advice to leave the possible ailment untreated) so you can protect people with bad decision making. Because many times, these tests will uncover things that obviously need treatment. They will save many lives. But because more stupid people will hurt themselves, then no one should have access to them. The political and moral assumptions built into these positions are immense and yet the medical field tucks those away and pretends that this is just a purely scientific truth, that someone running more harmless tests is actually inherently harmful. That is a lie! And a very nasty one at that.

ArtRichards 5y ago
If thats how you feel, I invite you to slapsgiving this year! Exactly 18:32 on the eve of Thanksgiving.
TaupeRanger 5y ago
Lots of problematic assumptions in your reply. >If finding something that otherwise carries no symptoms is best left untreated, then the fact that you found it should make no difference to the decision. The doctor should say that the best course of action is to do nothing. More information can never be harmful. Absolutely and demonstratively false. There is an entire field of health policy that destroys this harmful idea. First of all, just because something doesn't carry symptoms NOW doesn't mean it won't carry symptoms LATER, but doctors can't always predict this and aren't perfect decision making machines. Many times the patient will push them for further tests and treatment (or the doctors will advocate for it to ease the mind of the patient) which leads to potential harm from unnecessary treatments. And this is just ONE of the ways patients are harmed by unnecessary screening. There is also the psychological damage of having a condition you wouldn't have otherwise known about, and living with that knowledge (take aneurysms for example). Psychological stress has a real physical toll on the body. Then there's the COST associated with unnecessary screening and treatments, which (especially in the US) can run into the thousands quite easily for even simple interventions as a result of unnecessary screening. Even after that, a screening process can also find something that could be bad, but in some patients doesn't actually decrease their lifespan or quality of life. If we have no way of adjudicating between these cases or predicting which cases will end up bad if left untreated at the present moment, what do you think will happen? People will ask to be treated anyway, and iatrogenics will rear its ugly head. You cannot ASSUME that screening is automatically good. It must PROVE itself as such in a randomized clinical trial. This trial must show that people live longer and/or better as a result of this intervention. In many well documented cases, this turns out NOT to be the case, which entirely destroys your original rebuttal.
- throwawaynotmd 5y ago
  >Many times the patient will push them for further tests and treatment (or the doctors will advocate for it to ease the mind of the patient) which leads to potential harm from unnecessary treatments. >People will ask to be treated anyway, and iatrogenics will rear its ugly head. I just want to say that you are in agreement with my position here. Your point about psychological problems is interesting, but as long as people know what they’re signing up for, it’s okay. Some people aren’t prone to anxiety. Why should they pay the price because other people are? Part of my original point was that implicit in your argument is that people capable of handling it should be denied something because more people incapable of handling it can’t be stopped from hurting themselves. I think many people do not agree with that moral reasoning, so medical people hide it behind objective looking statistics. And as for cost, I don’t take any arguments from medical people about cost seriously. The reason why costs are so high is because doctors and the medical field as a whole run a massive protectionist racket to keep the supply of medical professionals low. How fresh of them to say that because they’ve limited the supply of medical resources to enrich themselves, patients must pay by having less access to care.

BurningFrog 5y ago

Iatrogenics is when a treatment causes more harm than benefit.

plank_time 5y ago

Utterly wrong. You are conflating current technology like MRIs and CT scans that only detect lumps, to blood tests that detect CANCER. Yes, if every lump were treated and excised then it would be problematic. But CANCER is different. The only cancer that you might be able to leave alone is prostate because it grows so slowly. Everything else is a risk. And if we can treat cancer at early stage 1, then maybe people won’t be as afraid of it because it has such a high rate of cure. We don’t know that until we do it.

TaupeRanger 5y ago
You say "utterly wrong" and yet you clearly have no idea what you're talking about and have never even approached the field of health policy. Screening has to PROVE that it makes people live longer or better, just like any other intervention. It is not the case that screening is automatically good, otherwise we would be giving 20 year olds colonoscopies. Just because you find something, doesn't mean you've helped the patient, as anyone with a modicum of understanding in this field knows. Read this and learn something: https://www.bmj.com/content/352/bmj.h6080 https://www.bmj.com/content/352/bmj.h6080
- plank_time 5y ago
  We don’t give colonoscopies to 20 years olds because it’s an expensive, invasive test with a low rate of cancer. We don’t give mammograms to under 40 year olds these days because the same and it’s notoriously inaccurate. We give blood glucose level tests and cholesterol tests to everyone every year at the physical because they are cheap and easy to administer. Even though the effects of both may take decades to have any effect and have no correlation to ultimate death. It’s about trade off of cost and convenience. If you detect pancreatic or colon cancer in a 20 year old patient via $1 blood test, that is immediately actionable. Cancer is ALWAYS actionable unless you’re talking about prostrate which grows slowly. But even in a 20 year old, you would want to treat that but maybe not a 70 year old. And we’ve never had the ability to detect stage 1 cancer of the deadliest types of cancer. Imagine the new treatments that might save lives if we could. Honestly, the number of people here who think they know better and citing unrelated research is bordering on anti-maskers parroting the surgeon general saying masks don’t work when they do.

Silhouette 5y ago

Mass screening of healthy people will result in ... But you don't know they're healthy. They might be sick but (so far) asymptomatic. That's why you screen, if you have a sufficiently accurate test available and you can make a useful intervention if the test gives a positive result. If we applied your argument consistently, we would abolish all cancer screening programmes, resulting in many extra deaths because early detection and treatment didn't happen. We'd stop checking up on heart health as people age, resulting in many extra deaths because people continued to live unhealthy lifestyles without realising what it was doing to them. We wouldn't be using rapid testing for COVID-19 to detect and isolate probable asymptomatic carriers who might spread the virus to others who wouldn't be so lucky. The list goes on. Good screening programmes save lives. It's as simple as that.

fallingknife 5y ago

I think it has more to do with how the kind of data collected from those mass screenings could be used to build predictive disease models that would put a lot of the guys making >= $300K to do a very poor job of keeping people healthy out of business.

treeman79 5y ago

I had a mystery illness. Spent hundreds of thousands on Er visits only to find it’s was a pair of fairly common conditions acting together. Blood work tests exists for both. A deep round of blood testing would have saved everyone a lot of time and money and suffering. Or I could have waited many years until the organ damage was so extensive that diagnosing was easier. Oh wait, that’s what ended up happening.

daemonk 5y ago

I understand this argument. But if we separate out the mass screening/data-collection approach from its practical constraints (undue stress, overwhelm medical system), I think we can both at least agree that it is a correct direction to head towards? Or is the status-quo already as well optimized as it could be?

iNane9000 5y ago

As it stands wealthy people can and do find more thorough medical treatment, including more frequent and exhaustive imaging, labs, etc... The conventional wisdom you cite only applies to those who can’t seek endless second opinions from specialists. There are many conditions that exist and are treatable in wealthier societies. The poor suffer those same afflictions but are untreated or misdiagnosed.

AlexCoventry 5y ago

If we optimistically assume the claimed 0.5% false positive rate is accurate, and all of the US got tested annually, that's 1.64M false positives per year. Cancer.gov is telling me that approximately 1.8M USians were expected to get cancer last year. That's a positive predictive value of 52%. That still seems highly informative, to me; much higher than the PPV for mammography according to this (admittedly old) study: [1]. Assuming the 0.5% FP rate holds (again, I know that's optimistic), would you still regard universal testing with this method to be harmful? [1] https://jamanetwork.com/journals/jama/article-abstract/409356 https://jamanetwork.com/journals/jama/article-abstract/40935...

TaupeRanger 5y ago
Good question. The proof is in the pudding. Run a well powered RCT and if the intervention helps patients live longer and/or better, then we should consider using it! It will be hard to design a study that includes all possible detected cancers, but there are ways around this - perhaps we begin by studying those cancers that are most common and lethal, and go from there.
amelius 5y ago
Isn't this exactly why the headline reads "blood test good enough to be rolled out"? I.e., higher FP rate, and it wouldn't be rolled out.
- AlexCoventry 5y ago
  IIRC, the actual article says they're going to do a large trial, with 150k people, and someone in the article expresses skepticism that the estimated FP rate of 0.5% is accurate, because so far it was tested in people where there's some evidence of cancer.
dan-robertson 5y ago
Is that actually good though? It feels to me that there’s a big difference between explaining the implications of a positive result to someone who understands bayes theorem and someone who doesn’t. Another aspect of cancer screening is that detecting cancer earlier can improve key statistics like 5 year survival without affecting the actual disease in any way. Which can make screening sound more effective than it is.

handmodel 5y ago

I'm not sure. I weight myself everyday. Some people tell me not to do that but its honestly pretty good at keeping me in check and because I weigh myself everyday I know that sometimes I just get super bloated and put on four pounds of water and it will be gone in a couple days. When you get more data you learn to adjust how you interpret it and make better decisions. Likewise, if getting a false result 50% of the time becomes common (this assumes we never improve the tests) then people will know to adjust their priors. After all - I've had to go to specialists a few times for extra tests. I wouldn't say we ban those.

shard 5y ago
Yes. I meticulously tracked every calorie I ate for several months. Now I know how much of different types of food is how many calories, how many calories I eat per day, and most importantly what my different hunger levels mean in terms of the number of calories ingested. Combined with my weight tracking, which tells me my set weight / weight variance over a day or several days / food intake to gain or lose a certain amount of weight, I can easily control portions to hit my weight goals without thinking about it. I would imagine more health data would allow me to optimize in this fashion as well. If I can correlate health markers to my lifestyle often and directly, I can make better and more informed choices. Advocating against easy access to health data because some people can misuse it is the same kind of nanny state thinking that says encryption shouldn't be available to the masses because criminal enterprises can use it to hide their activities.

theptip 5y ago

While I agree with the point that you're making around employing caution against iatrogenics (with colonoscopies being a very good case study that one should make sure to understand before forming an opinion here, as you referenced in another point), I think you're overconfident in your prediction that this hypothetical scenario would be bad. I think your claim (based on sibling posts) is that in the current medical system, if we just added more screening, we'd not necessarily get net benefits. But I think that ignores the fact that, if we had cheap and high-resolution screening, we could fundamentally restructure many aspects of medical care. The BMJ article you linked in a sibling[1] notes that cancer screening may reduce cancer mortality but increase all-cause mortality. That's an unexpected and problematic result of getting referred to a cancer specialist that might not have (or be incentivized to care about) a wholistic picture of health when you screen positively for cancer. But if we had higher-resolution data, and conceptualized medicine as primarily preventive instead of curative, then it seems likely to me that overall mortality would be your target, we'd have richer data to be able to track that endpoint, and so we'd be more likely to catch the cases where an intervention caused unexpected harms (because we'd be tracking more indicators). In other words, the problem you're observing is that adding a bit more data to the current system can produce negative outcomes. But that problem would be fixed by adding even more data. (With the remaining question being, how much data would we need to add to reach the "net positive" regime?) I think you're arguing against a change that looks like a harm from the perspective of a local optimum that we're currently working towards, without considering the dramatic paradigm shift into another higher-utility region that would have been brought along by this sort of technology. In summary, I am much more optimistic that if we had orders of magnitude more data, we'd make better decisions, not worse. But I agree with your caution that it's not as easy as it seems. [1]: https://www.bmj.com/content/352/bmj.h6080 https://www.bmj.com/content/352/bmj.h6080

fierro 5y ago

this is a paternalistic point of view. People should be entitled to accumulate data about their own body -- any "negative" ramifications of this are personal problems.

soheil 5y ago

I wonder if the equivalent of extreme iatrogenics and unnecessary psychological damage and stress also occurs when monitoring servers too much. I have a feeling it does. This is why I typically set higher thresholds like more disk space, memory (equivalent of exercise and healthy diet?) that I really need so I stop monitoring my servers religiously.

LightMachine 5y ago

This mindset kills more people than Hitler. Have a good day.

lhorie 5y ago

I think you're casting too wide of a net there. Just because you've detected something early doesn't mean you automatically need aggressive interventions like chemotherapy. The impact might just end up being a line in your medical record for the family physician to keep an eye on during yearly routine exams. Breast cancer awareness programs are a good example of early screening programs not being an exercise in mass hysteria. Some early symptoms for eye conditions only require periodic observation up until it actually becomes a problem. Etc. Perhaps it is true - in the US, anyways - that there's a tendency to overly prescribe more aggressive interventions (read: more expensive ones), but my understanding is that the US model is the exception, not the rule, when looking at the rest of the world.

vharuck 5y ago
>Breast cancer awareness programs are a good example of early screening programs not being an exercise in mass hysteria. This example also shows how screening can be recommended against because that's better for public health. The US Preventive Services Task Force (indirectly decides what Medicaid/Medicare covers) has different recommendations than the American Cancer Society for how often women of certain ages should have mammograms. USPSTF recommends against routine mammograms for women aged 40 to 49 if they don't have other risk factors. ACS recommends biannual mammograms start at age 45. The reason they differ is because of how they weigh the reduction in deaths against the harm of false positives. Routine mammograms will prevent breast cancer death, no doubt about it. But notice neither recommends routine mammograms for all women below 45, even though they accounted for over 10% of breast cancer diagnoses in 2014-2018[0]. The math is tricky when comparing a risk of death against quality of life and economic costs. Public health is a matter of public policy as much as health. [0] https://seer.cancer.gov/statfacts/html/breast.html https://seer.cancer.gov/statfacts/html/breast.html
throwawayboise 5y ago
"The impact might just end up being a line in your medical record for the family physician to keep an eye on during yearly routine exams." And something to be on the back of your mind as a worry forever. I'd rather not know.

Buttons840 5y ago

> so by detecting it early you are just reducing the amount of life they have left without worrying about their disease I wonder if people would rather continue to live care free, spending most of their waking hours commuting and at work, or if they'd rather learn the truth and face the harsh reality that their time is about up and adjust their priorities accordingly?

throwawayboise 5y ago
Nobody knows when his time is up. You could be hit by a truck on your commute to work. I would rather live my life as it comes, for whatever length of time fate has given me.

captainmuon 5y ago

If you leave the treatment criteria the same, then yes, you are absolutely right. But you have to adjust those, too. Just a made-up example: Let's say someone has an advanced test for cancer run, and it comes back positive. You know from studies that treating people the same way as before with the advanced test leads to worse outcomes because of unneccessary treatment etc.. So what you could do is you do the simpler test afterwards. If it comes back negative, you don't treat -> you are in the same situation as before, only you can be more vigilant in future and see if the cancer grows. If the simpler test also comes back positive, you do the treatment. It's all about getting data (statistical and otherwise) on what the best treatment is, and acting on that.

nyokodo 5y ago

> Actually you don't want this, and you are describing a nightmare scenario that everyone who studies health policy understands all too well. Would a very large representative sample of volunteers doing this kind of hitherto unprecedented level of medical monitoring help improve this technology while limiting the unintended consequences? If we could get to the point where the technology was very highly predictive of specific outcomes and even had the ability to test early interventions on those outcomes, that would both allay the psychological cost of a population-wide roll-out and drastically improve outcomes across the board, would it not?