Doing a CT or PET scan just for fun is not a great idea, because of the radiation dose received.
However, MRI is completely benign. It doesn't expose patients to any dangerous radiation and is minimally intrusive (you just need an IV for contrast).
The justification "but then we'll have to check the findings!" is super-weak.
No, it's not at all a weak justification, and it is the primary reason you shouldn't get these scans done.
The problem here is our old friend the Bayesian Base Rate fallacy. The diseases you're looking to intercept and intervene against are, in the general population, pretty rare. That means that even if the indications you'd get from diagnostic imaging are extraordinarily accurate (they aren't), the overwhelming majority of the flags they raise are going to be false positives.
The cost of a false positive imaging flag is far worse than having to have an unpleasant chat with your doctor, or worrying for several weeks (do not discount the cost of worrying for several weeks, though; these scares can absolutely fuck up a month of your life). Rather: you'll pay the price in follow-up imaging, which won't be as benign as the MRI, or worse, in unnecessary intrusive diagnostics.
It's has nothing to do with the Bayesian Base Rate fallacy.
In this case we ABSOLUTELY KNOW the base rate is lower, since it was a preventative scan. The fallacy only happens if you then subsequently fail to adjust for the differing base rate.
If doctors later in the diagnostic process fail to take the differing base rate into account, that is not the fault of the preventative test, that is an error in determining what the correct follow up care is.
> If doctors later in the diagnostic process fail to take the differing base rate into account, that is not the fault of the preventative test, that is an error in determining what the correct follow up care is.
In today's medical malpractice climate, many physicians intentionally ignore the differing base rate.
Most people aren't going to be happy with "the scan shows something unusual that would normally be concerning, but you say you feel fine so I'll trust you instead of the scan".
I suppose that's fair way to look at it, but people are being left with the impression that the problem is inherent in the tests, when the problem is entirely separate from the tests themselves.
I suppose it's a fair way to look at it, too! It's good when we can reach a shared understanding of what's happening; so often, the dynamics of message boards work against that.
What is the base rate of a not-very-suspicious-but-maybe-a-little-bit finding on imaging of an asymptomatic person in the general not-sick population?
I think pretending that medicine is equipped to deal with this in a healthy way is stretching the limits of well established medical science, and beyond what I would expect even a well intentioned and astute physician to know how to approach (or at least have been trained to do so expertly).
Not that you're wrong, you're not, strictly speaking.
"Suppose that at your regular physical exam you test positive for Disease X.
Although Disease X has only mild symptoms, you are concerned and ask your doctor about the accuracy of the test. It turns out that the test is 95% accurate. It would appear that the probability that you have Disease X is therefore 0.95. However, the situation is not that simple."
> No, it's not at all a weak justification, and it is the primary reason you shouldn't get these scans done.
Yes, it is weak. The so-called downside is that you might need to do intrusive procedures as a followup.
But guess what? You don't HAVE to do that.
> The cost of a false positive imaging flag is far worse
Now think about the costs of not detecting a true reading. Most cancers start having visible symptoms only when they are far too advanced to be cured.
So the status quo is: you wait until you get an incurable disease, and then use MRI to solemnly confirm that. And then use it to give you estimates on how soon you'll die.
> Rather: you'll pay the price in follow-up imaging, which won't be as benign as the MRI, or worse, in unnecessary intrusive diagnostics.
Or you can just wait for a bit and do another MRI to check if there's any worsening. If you can afford an MRI, you likely can afford a second one.
I read your comment and was all ready to write a, I guess, rant about joint probability distributions and costs associated with tests and on and on. You know, a good old rant. But I took a moment to actually read the article. Low and behold, the first line, or perhaps the actual headline,
"Wealthy People Are Getting Full-Body Scans. Early Detection or Unnecessary?"
"Wealthy" appears 3 times. Multiple allusions to income, "summer in the Hamptons" and such.
I'd need to reflect a bit, but I think I'm pretty comfortable with applying FDA requirements and prohibiting any health claims, but feel free to let the snake-oil salesmen fleece away.
Point is that if you know that overwhelming majority of the result are false positives so that it is not worth to follow-up them with additional diagnostics, then reasonable step is to not follow-up in that case.
It is a fallacy to account the cost of follow-up procedure to the initial scan, when the follow-up procedures are not necessary regardless of the result from the scan.
> then reasonable step is to not follow-up in that case.
Then a more reasonable step is not to get the scan. Why do the scan if you don’t follow up.
This is why not all screenings are recommended. People think that insurance won’t pay for scans because insurance is a jerk. They don’t pay because the scans aren’t medically effective at protecting populations.
Follow up procedures should be adjusted based on whether the original test was preventative or not, titrating the amount of risk and cost appropriately
The fact that we treat diagnostic results the same regardless of priors just means our medical system is still stuck in the stone age
Saying the screenings aren't recommended is just saying "we're too dumb to use the results of this screening the correct way, so you shouldn't get the screening"
We can only hope that the new developments in AI will mean that modern statistical procedures will finally be applied to medicine as a side effect (though I wouldn't hold my breath)
The point is that if you know the test has so many false positives that you're going to ignore the results, just don't run the test. What's the point of running a test if you're never going to follow up?
You can follow-up when it's warranted. See the below anecdote. I'm guessing as to the details, but perhaps the thyroid was cancerous early, but it was too indeterminate, so they did nothing. But then when it started growing, they could change the approach. It's a piece of date, to weigh amongst the overall mix. The problem is most people will demand too much action.
"Bob Nelsen says that he has a family history of cancer, so began getting annual Prenuvo scans around 10 years ago.
- The early scans showed a nodule in his thyroid, but doctors didn't believe it was problematic. Then a scan in 2018 showed that the nodule had changed, which isn't supposed to happen in healthy people.
- "When I went into Stanford for surgery, I asked how many patients they'd had with five years of longitudinal data on their thyroid, and they said I was the first," Nelsen tells Axios. "The medical profession is trained to be reactive, not proactive."
- He adds that the scans also discovered a small scar on his brain, which he assumes came from falling off his bike and getting knocked out when he was 11 years-old."
You know whether or not it's warranted before you run the test. That's the whole point of the discussion around when preventative testing is appropriate. The key is that the test is just one additional data point. Before running the test - you want to make sure that the data from the test will be useful for whatever purpose you want the test for (false positives could be ok if the point is to minimize false negatives). That way when you run the test, it's always "warranted" to follow up if needed. We do mammograms for healthy seeming people all the time - it's totally feasible that we'll determine that these new approaches are informative enough to become recommended for the general public, but we're still on that scientific journey
You are misunderstanding how ‘incidentalomas’ are reviewed and managed. You don’t know it’s a false positive until you’ve done the invasive diagnostic tests subsequently (with non-zero risk), at which point you can classify it as a false positive
An issue that gets brushed over is you have various possible results to an invasive diagnostic test.
1. Bad
2. Indeterminate
3. Benign
4. Nondiagnostic
One and two are simple enough. Three and four are really problematic. And they are more common that people assume. Worse people confuse the two.
Indeterminate says they have a sample that is sufficient but can't be assigned to Bad or Benign. What do you do then? If you treat some large percentage will be treated for nothing. If you don't some percentage will see progression.
Nondiagnostic says there are issues with the sample that make a determination impossible at all. What do you do then? Repeat the biopsy? What if you get another Nondiagnostic? Forget about it?
Absolutely right! The WSJ article could have done a much better job on this topic but instead ends with a rare true positive cancer detection success by a for-profit scanning company. That one rare success needs to be weighed against NN false positives. And a fraction of the true positives might well resolve on their own.
It's really easy to demonstrate with some basic math too. All of the numbers below are pulled from memory from a textbook example:
Imagine you have a test with a 1% false positive rate when screening for a disease that has a prevalence of 1 in 1,000 and the invasive operation to confirm the diagnosis has a 10% chance of serious (potentially life altering) complications like internal infection or an embolism.
If you test 10,000 people, you'll identify 10 true cases (assuming 0% false negative rate) and 100 false cases. Meanwhile testing those 110 people will result in 11 patients suffering serious complications. Once you include the complicated math of quality-adjusted life years, it's almost never worth it.
In reality the numbers are a lot worse - there is a long tail of diseases with 2-10% false positive rate tests and 1 in 10,000 incidence or worse, with 20% of patients experience QALY effecting complications from false positives. On top of that there are a lot of interventions that require invasive procedures with low rates of success.
> Once you include the complicated math of quality-adjusted life years, it's almost never worth it.
This is an actuarial argument, that applies is you want to have the most efficient overall healthcare system. In other words, if you have to ration the access to MRIs and to followup tests.
Now suppose that you are not limited by scarcity. It would absolutely make sense to use the minimally invasive procedures, but perhaps weigh the results a bit less heavily for followup tests.
Yes, orthopedics has gone down this road. Intervention based only on imaging does not have the best outcomes. Not every abnormality is cause for alarm. Using genetic profiling and family history to decide who to check for conditions is not merely for the benefit of the at-risk; it is also to protect those who might show false positives from unnecessary interventions.
Hmm ... idk. I disagree with that (sort of) argument in so many ways.
>The disease [...] are, in the general population, pretty rare.
Cancer is not rare, particularly from a certain age. Early detection heavily skews the odds on one's side. This is such common knowledge that it feels weird having to justify it here.
I know I'm not a "survey performed under the most strict standards of quality" but among my close groups of friends and family there have been a few cases where they got lucky enough to detect this disease very early on, and their treatment and outcome was significantly better (and cheaper, while we are at it, bc you mention cost as well) than if they've just waited even a couple more months.
OTOH, I have yet to hear a story from someone who had some sort of scan done, found something worth to take a look at, that then turned out to be nothing and, for some strange reason, had its life significantly affected by that.
Doctors are not stupid, they know (or intuitively correct for) this Bayesian Base Rate you mention, plus they have other things like years of experience in their particular field. It's not like someone's going to cut your arm the moment you find a weird looking lump growing inside.
>these scares can absolutely fuck up a month of your life
That sounds quite immature, tbh. It's definitely a small price to pay compared to all the trouble you save by potentially detecting issues early on. "Oh, but needles hurt :'(", sure, but their benefit far outweigh such small nuisance. This is also an argument I would've thought anyone would just get naturally, and yet I have to explicitly bring it up here, weird.
Also, if it came to be the case that everyone got scanned regularly, that massive trove of new data would definitely help improve the accuracy of said tests. It definitely won't make matters worse, but better.
>OTOH, I have yet to hear a story from someone who had some sort of scan done, found something worth to take a look at that turned out to be nothing and that, for some strange reason, was significantly affected by that
The go-to for a lot of the "take a look at that" procedures is a biopsy, and a biopsy is not a risk free procedure. I'm surprised that you know more than one person that's had a full-body scan, but don't know anyone that's had a biopsy complication, I know one person who spent several days in the hospital on IV antibiotics after an infection after a Prostate biopsy (which was negative)
>>these scares can absolutely fuck up a month of your life
>That sounds quite immature, tbh. It's definitely a small price to pay compared to all the trouble you save by potentially detecting issues early on.
Have you ever had a cancer or other serious disease diagnosis? It can be surprisingly stressful and detrimental to your health even if it is something that can be effectively treated.
>The go-to for a lot of the "take a look at that" procedures is a biopsy
It's not, sounds like you're not familiar at all with any of this.
There's some road to cover from imaging -> biopsy. Blood tests, more detailed imaging, even keeping an eye on it for some time, etc...
Have you heard of Pap tests? A lot of them come out find signs which could be indicative of a developing cervical cancer. Do all these women get their cervix removed the next week? No, not at all. Most of the time the symptoms go away in a few weeks, after some care and treatment.
Pap tests are done for a reason. Pap tests are the single thing that completely obliterate the "screening everyone is bad" argument.
I have yet to see any of my radiologists differentiate a lung nodule that was actually a metastasis from the colon (which can easily miss on PET ) from primary adenocarcinoma/small cell/etc. Neither a pancreatic neuroendocrine tumor from an adenocarcinoma based on a CT or PET.
I have (and often) see my patients incidentally discover masses on imaging. Perfect example- a pancreatic mass on imaging. Next stop is an anxiety filled few weeks while they wait for their biopsy to be scheduled. You then have an additional radiation exposure as these are CT guided. You hope the radiologist doesn't poke a hole in a nearby vessel, induce pancreatitis just by doing the biopsy itself, nor develop a subsequent infection related to the procedure. They then wait an additional week for pathology to result, often only to see normal pancreatic cells indicating this is a cyst.
All of this is often the result of looking for a seemingly innocent diagnosis. Eg an ultrasound to reassure your patient that their abdominal pain is not their gallbladder.
I had a similar event earlier today with a cervical lymph node seen on an ultrasound.
Thyroid nodules, renal masses, lung nodules. How long do you have?
I got bloodwork done for the first time in a long time. My liver enzymes were high. I don't have hep C. I cut out drinking for a while, liver enzymes were still high. They did some imaging and maybe saw some fat on my liver. They did some more imaging later and didn't see the fat. Enzymes are still high. My next option is a biopsy, the hepatologists tell me.
If I do the biopsy and they don't find cancer or something, they'll just tell me to drink less and eat better. Seems like mostly downside to doing the biopsy.
> Cancer is not rare. Early detection heavily skews the odds on one's side.
Depends on the cancer and even the doctors are torn. Most breast tumors and prostate tumors will not kill you or affect your life much. Treating them likely will (especially for prostate). Depending on the model, the overall health of the population is actually reduced by early detection because in most of these tumors treatment is worse than the disease.
One of my doctors is a strong believer in periodic prostate exams after 40. The other recommends only if there are other symptoms. You can guess which is the older one and which is the younger one.
Years ago there was the whole Gardasil controversy. What was often excluded in the noise was that if it were mandated for all girls as some states were recommending, it would be so expensive that funding for other health programs would need to be reduced. The studies were showing that this kind of preventative approach would again reduce the health of the state's population.
Preventive medicine is good - to an extent. Beyond that it is bad.
Untreated detectable cancers still kill relatively quickly, the only time they’re not a major concern is when people have other major medical issues.
For perspective even with all the advances in modern medicine in 2020 and thus a pandemic, cancer was still the #2 killer in the US after heart disease. It killed over 600,000 Americans in 2020 and that’s a 27% improvement over what it was doing as recently as 2001.
That said, there’s currently believed to be a long undetectable period where the body fights off most pre cancers. We’re approaching the ability to detect cancers below 0.5mm which we don’t have much clinical data on.
> But that's a different thing. I'm sorry, I will not talk about that.
For people setting policies (and that includes doctors) cost is absolutely not a different thing.
If you can afford to pay for everything without involving insurance, by all means do whatever tests you want. If you're a doctor you don't want to maybe help Betty while definitely hiring Veronica.
> Most breast tumors and prostate tumors will not kill you or affect your life much.
This is yet another fallacy.
A prostate cancer takes about 10 years to kill you. If you're 80, then it's probably not worth pursuing aggressive treatment. You're likely to die of something else.
However, if you're 40 then it's another story entirely.
Untrue wrt prostate cancer. Since the average date it’s detected is 70 and 2/3rds of the population is obese, then of course most people will die of something else. If you are non-obese and in good shape, then get aggressive treatment.
The Cochrane collaboration (2013) states that the best quality evidence neither demonstrates a reduction in cancer specific, nor a reduction in all cause mortality from screening mammography. When less rigorous trials are added to the analysis there is a reduction in mortality due to breast cancer of 0.05% (a decrease of 1 in 2000 deaths from breast cancer over 10 years or a relative decrease of 15% from breast cancer). Screening over 10 years results in a 30% increase in rates of over-diagnosis and over-treatment (3 to 14 per 1000) and more than half will have at least one falsely positive test. This has resulted in the view that it is not clear whether mammography screening does more good or harm. Cochrane states that, due to recent improvements in breast cancer treatment, and the risks of false positives from breast cancer screening leading to unnecessary treatment, "it therefore no longer seems beneficial to attend for breast cancer screening" at any age. Whether MRI as a screening method has greater harms or benefits when compared to standard mammography is not known.
I also couldn't guess. There are equally plausible stories the other way: "obviously the older one is the one who doesn't recommend, since they're more experienced and have seen over thousands of patients how often it doesn't help...".
> What was often excluded in the noise was that if it were mandated for all girls as some states were recommending, it would be so expensive that funding for other health programs would need to be reduced.
This is an argument from scarcity. If you have a severely limited amount of a resource, it makes sense to sacrifice some people, so that more people can receive life-saving care.
If the resource is not scarce, then this simply doesn't apply. These days HPV vaccine (in Europe) is around $30, so it makes sense to just vaccinate everybody.
> Preventive medicine is good - to an extent. Beyond that it is bad.
Nope. It's always good, but sometimes it's too expensive.
> These days HPV vaccine (in Europe) is around $30, so it makes sense to just vaccinate everybody.
These days it's likely a very different from 2007 when it was being debated.
There argument wasn't that no one should get Gardasil. Just that it would hurt the health of the society if it was mandated for all. Obviously if you had the money it's good to get it
Yes, and this argument indeed holds in the case of extra MRI screenings. We simply don't have enough MRI units to screen everybody every year.
On the other hand, the quantity of MRI units is not fixed. We can always build more, they are just inherently very expensive. And if you can afford an MRI scan from your personal disposable income, then what's the problem?
> I have yet to hear a story from someone who had some sort of scan done, found something worth to take a look at that turned out to be nothing and that, for some strange reason, was significantly affected by that.
Silly comment. They tell you there's a 16% false positive rate. Maybe you don't know any of these people, but I'd certainly be willing to bet money that some of them got worried sick about it.
In addition, an older case is prostate cancer. At least in the older days, they would do painful procedures that left the patient with significantly lower quality of life, when in fact, many men with prostate cancer die of something else. Nowadays they're a little smarter about it.
> OTOH, I have yet to hear a story from someone who had some sort of scan done, found something worth to take a look at, that then turned out to be nothing and, for some strange reason, had its life significantly affected by that.
My friend's wife had a scan done when she was 55 and they found "something they wanted to look at" in her breasts and needed to do a biopsy.
She has anxiety. Her blood pressure spiked to a dangerous zone. It stayed elevated even as they tried to control it with medication. It didn't go back to normal until the biopsy came back negative.
During that time, she was at significant risk of having a stroke or heart attack. All for eventually nothing.
Things like women who have a small cancer that is treated with suregry and quick radiation but insist on getting a mastectomy are not rare, either.
> Her blood pressure spiked to a dangerous zone.
> Humans are not rational.
total anecdote but every time i go in for a yearly health exam my blood pressure and heart rate goes up, especially right before sitting down to get my blood pressure taken!
if i take it myself, for some reason im not nervous, comes out ok...
I have a very hard time believing that your friends and family are getting PET/MRI scans routinely, as opposed to what most people actually do which is "hey I found this lump/I feel bad here, please can you check if this is bad and scan for anything else?"
This is an important distinction, because you can delude yourself and your medical team into believing you are healthy because you had a clean scan x months ago, as part of your annual deep checkup or whatever you want to call it. Leading into that part of if your friends had waited a couple more months it would have been a very different outcome!
Seems plausible. So what's up with the wealthy? They do not care? They do not know? They get talked into it by greedy physicians? Or is the story more likely just not true?
Well, it's not as if wealthy people are any different from the average Joe. They may go on HN instead of FB for their medical advice (and I've seen these sorts of scans advocated in comments here, to be clear), but that doesn't mean they have any more knowledge of outcomes for these screenings. What they do have is a knowledge of their own (and parents') mortality and means to do anything they can to prevent it. Buy a bunker in NZ, try to build a base on the moon, or spend a couple grand on a frivolous scan? Rich people gonna rich people.
Yes, the medical system in the US is for-profit and fee-based. Medical providers make money by building small businesses which do a lot of procedures. Here is another very expensive, uncovered procedure for them to bill.
I've noticed that many educated people expect other, otherwise educated people to not exhibit certain dumb behaviors. In reality, people are people. They will do dumb shit regardless of how rich or educated they are.
They can afford it. And they are able to pay for anything medical their doc recommends.
I am curious but not willing to spend $5-20k in scans and tests. Especially since they can be done annually. Why not? There’s no medical guidelines for what period has higher positive impact.
My doctor has mentioned tests that cost thousands and have a low probability of useful information. I say no. If I was rich, I’d probably do any test if the only downside was cost.
> The problem here is our old friend the Bayesian Base Rate fallacy. The diseases you're looking to intercept and intervene against are, in the general population, pretty rare.
This is pseudoscience at best and quakery at worst.
Body is not a Kubernetes cluster that can be restarted or reprovisioned from scratch when it has become too late to fix an aling pod or a service on the spot.
Physiological processes taking place in the body are more akin to stochastic processes whose behaviour can be accurately projected only to a certain extent (the extent varies depending on what the actual process is) based on levels of our current (but evolving) understanding of the biochemistry and phsysiology. Therefore, our bodies require a set of anomaly detection monitoring alarms, of which preventive health scans (whatever that means, not just CT/MRT/etc) are one example. If one such stochastic process goes awry, it can trigger an irreversible cascading failure in the body with the only outcome: premature death.
Take inflammation as an example. Inflammation is a root cause of multiple severe as well as degenerative health problems that impair the healthy aging of the body. Inflammation is notoriously difficult to detect via conventional testing means such as blood tests, unless somebody is looking for a specific inflammation biomarker. Routine blood tests do not do that (other than checking the monocyte and eosinophils counts), and when the inflammation reveals itself, it is already loud (pain or impaired wellbeing) and severe (a heart attack) or it is already too late (late stage cancers).
Inflammation starts out small and incospicous, and it takes a long time to progress and develop into something more unpleasant. Alzeheimer's, Parkinson, cancers, heart disease, IBS and many, many other health conditions have all been implicated to be caused by chronic inflammation processes that went undetected and were allowed to unfold, with plenty of sufficient (although not always fully conclusive yet) evidence. The vast majority of people of this planet are thought to have inflammatory processes going on of varying degrees of severity – from benign (that the body eventually suppresses) to malignant.
If a routine preventive health scan can unravel an inflammatory process early on, it is a win – for the patient (improves the long term prognosis and the quality of life) and for the health care system (early treatments are usually simpler and are more cost efficient, therefore less or no expenditure later).
Even if a preventive health scan is a false positive, it is still a net positive, is a net win as it indicates the lack of a health problem, and it is long term investment that time, effort and money for everyone.
yes but the expected value of having a true positive is infinite because it saves your life. so that seems to outweigh the cost of false positive even if that’s more likely
Doing an MRI without contrast is probably benign (and typical of what you would do for sports injuries), but gadolinium contrast is likely to be reevaluated in the near future, as it is a toxic heavy metal that is not fully removed from the body, even in its chelated form [0]. If you ever had a brain MRI with contrast, you would know it's a lot worse than a typical hangover, which is usually not a great sign for health impact.
Unless you use a contrast dye--which is basically needed to be useful at spotting anything.
And an MRI will find something. So, the real problem is that you now need 3 or 4 followup MRIs over a period of 2 years to classify them as benign or not.
It's a tough decision to make even if you have the money - PET scans use a radioactive tracer injected in your blood that's like 5 years worth of radiation in one day. It can detect cancers, but yea that's an unsettling amount of radiation.
Then there's the risk of them actually finding something, which is very stressful, requires biopsies, potentially surgery, etc.. for something that could actually be benign.
My gf did it already with no issues luckily, but I haven't been able to rationalize doing it myself.
It's an MRI, there's no radiation. And I understood these scans look for changes more than specific structures, so have fewer false positives than just a one-of
In terms of people getting preemptive scans, hospitals around the world offer PET/MRI/CT, etc.. basically an a la carte menu of diagnostics. To find cancer early you want PET.
This article centers on an MRI company, who I’m sure tout the lack of exposure from MRI.
If you’re going to get a PET scan, might as well do full-body, and make it PET/MRI. A PET/CT will reach 5-8 years equivalent of ambient background radiation.
I wonder if there's a difference between internal and external radiation. 8 years of radiation internally in the space of a day has got to be worse than 8 years of external radiation slowly.
They offer MRI combined with PET. They give you a high dose of iron for to see things better in the pancreas. PET scan uses like radioactive sugar to find hungry cancer, even tiny ones. MRI is used to find large scale structural problems.
Personal anecdote: The wife of someone I know got a full body scan in Germany (because they were outlawed in the Netherlands, don't know if they still are). Clean bill of health. About 4 months later she was in the hospital with cancer.
Damn, one of the worst parts about cancers is that there isn’t information on how fast they grow unimpeded, so that messes up knowing what interval would be best
Its like a fetus growing in the wrong part of your body, several weeks go by and you’ll have an organ problem
I read the full body scans are not entirely accurate compared to specific/localized scans. But definitely helpful, for example I read x-rays don’t pick up lung cancer until much later. Whereas mri’s will pick it up?
CT and the PET scans are the most accurate cuz the liquid will light up but itself has a prevalence of causing cancer, higher chance the younger the individual is.
Also this xkcd is great at illustrating radiation doses
I think since the scan practitioners know their customers are all “tourists” and they aren’t regulated for accuracy (they aren’t part of guidelines and medical review) not cost effectiveness (insurance won’t pay) I wonder how seriously the interpretations are.
If if you’re a great radiologist, if 999/1000 scans are just of healthy rich people you might not stay vigilant.
Do doctors want to gatekeep technology to make sure they get a cut every time someone uses this machine? This seems to be sending a signal to the market for more competition of scanning technology so I can see this driving the price down for everybody in the long term.
People will disagree but I think a lot of it is people angry that some can afford it and some cannot. In Canada we have only public healthcare, so everyone gets the same poor government service (unless you are rich enough to go to the US or know the loopholes). And people fight tooth and nail to keep it that way, in the interest in fairness. We recently has a court rule that even though people will die because of the absence of private options, that's an acceptable trade off to enforce "one-tier" universal healthcare. I'm sure doctors wanting a cut is another root cause, but a lot of it is just jealousy.
Healthcare in Canada has many problems but being "public" is not the cause of them. For decades conservative governments have underfunded the medical institutions in my municipality as a way of making true on their promise of lower taxes. Now the hospitals here are understaffed for the wave of infections every year and the staff is overworked. Things could be better if people stopped chasing lower taxes every election and actually thought about where that saved money was going to go. It doesn't need to go private. Although the Ford government in Ontario seems set to lead the province in that direction by continuing the legacy of conservative governments.
Canada isn't the united states, hyperpartisan "conservative governments" nonsense is just ignorant. Our political parties are exactly the same, both support our third world healthcare system as is because it favors entrenched interests and it's politically popular. But don't let that get in the way of playing American and blaming "conservatives".
"both parties are same" is either an incredibly disingenuous interpretation or ignorance, and I can't tell which. Yes, they both ostensibly support the healthcare system in that the CPC doesn't want to say that they want to get rid of it, but you just have to look at the provincial parties recent actions to disprove the "sameness". I even gave you an example. Things don't need to be stretched at much as in the US for the two parties to employ different strategies towards healthcare.
Also I don't think you know the definition of "third word".
>"people will die because of the absence of private options"
Private options are available for Canadians. Just cross the border. Problem is that your generic Joe Six Pack can not afford it. If they open private in Canada the Janes and Joes still would not be able to pay for it.
Private insurance in countries with a primarily public healthcare system seem to be relatively affordable in general.
I guess it makes sense because young professionals who get it as job perk are overrepresented in the pool and pretty much all serious/very expensive issues will still be covered by the private system.
Are they gatekeeping? We saw how recommending mammograms earlier and earlier was not a great benefit. Medical arts aren't always just magic and more isn't always better.
My mom had cancer that was treated. The official correct follow-up was to get checked to make sure it didn't come back every 2 years. At the 2 year check it was too late and untreatable. I no longer trust doctors/advisory panels and their 'statistically what's best' and never will again. It cost me my mom. I just want my mom back.
I'm sorry for your loss, but if it progresses that far, that quickly, it very likely would have killed her in almost exactly the same time frame even if you had followed her up every six weeks, which is why the "statistical best choice" is often to do things less aggressively.
I've seen discussion about this. It seems the general opinion among doctors is that full-body scans for everyone would be a bad idea, because most people have some structural anomalies inside that shouldn't be a concern but would make people anxious anyway.
Hard to say. Consider a patient without complaints with a scan that shows an abnormal bleb in or on the head of the pancreas. Physician 1 thinks it could be a pancreatic tumor given patient age and family history. Physician 2 thinks it is more likely to be a minor lifelong development anomaly with the bleb actually being an intrusive bit of the spleen.
Is exploratory surgery needed? Watchful waiting?
An acquaintance of mine with the second harmless condition had the head of his pancreas removed and he has suffered greatly for over a decade. Almost killed by FDR misinterpretation.
I like this example because it doesn’t rely on the US oddities that people often come up with for this topic (eg doctors doing extra, likely negative EV, procedures for fear of litigation).
No because the doctor can be successfully sued for not ordering the followup even when the followup would not have been in the patient's best interests. I.e., juries are irrational.
How would it be? Again, the base rates of a lot of these conditions are very low, but not low enough to say "this is a zebra, not a horse", so I think a suspicious lump is likely to trigger a CT, PET, or (in the worst case) a biopsy.
I don't understand what "base rates" means in this context.
If you have a test result, that you think is showing something with a certain probability, which is higher then the current necessary confidence level required to trigger further probing, and it turns out afterwards it was a false positive, my naive way to go about this would be to raise the minimum confidence level afterwards (and vice versa if it's a true positive)
Does this fail in horrible ways that I am missing right now?
It's not just the anxiety and psychological distress either. If we scanned everyone all the time, you would find literally millions of conditions that would never cause symptoms or major health issues, but would nevertheless be treated unnecessarily, incurring massive additional costs and needless interventions with their own risks. It would be a nightmare.
This doesn't make any sense to me. It's either a problem or it isn't unless doctors are willing to admit they perform lots of unnecessary procedures already.
Let's say you have a mass at the head of the pancreas that is incidentally detected on a scan. Let's further stipulate that the mass does not have anything that clearly indicates that it's pancreatic cancer - but also does not have signs of being a benign cyst. What do you do about it?
Well, you can do nothing, and just follow it up with repeat scans. Or you can go to surgery. Both cost money and time. But if you have pancreatic cancer, aggressive resection is essentially the only chance of a cure. So both patients and doctors are highly incentivized to go straight to surgery. If it turns out, once the mass has been resected, that it's actually a completely benign tumor, was the procedure really "unnecessary"? Because taking a piece of it and looking at it under a microscope is the only way you'll ever know for sure.
Would you like to try live your life normally with that sword of Damocles hanging over your head? I wouldn't.
That's vacuously true. The problem is that we humans can't always discern the truth of the situation. Not even doctors.
They perform a lot of unnecessary procedures. It's well known and not a conspiracy. Sometimes they do it to make money. Other times it's so they don't get sued. Scan the comments here and you'll see sentiments of people upset that their doctor didn't do a procedure and blaming them for adverse health problems.
Because sometimes it is. This is widely understood in health epidemiology. There are no screenings or interventions with zero risk: https://www.bmj.com/content/352/bmj.h6080
Information’s value is based on the value of decisions made from that information.
That’s how procedures can have negative value.
This isn’t even just the cost of storing and retrieving useless info. Sometimes decisions get harder the more irrelevant information you have.
So it’s better to act on less information than to get more bad information.
In the case of body scans, the harm comes from more expensive followups or treatments to rule out false positives.
Most things that have net value from screenings are already recommended so if it saved lives, it’s usually already recommended until new research changes the calculations.
I think it’s useful to look at the overall behavior change that happens with a thing.
I mean I guess lung cancer isn’t a problem with cigarettes, it’s a problem with people smoking lots of them.
Body scans don’t provide useful information due to their false positives. Maybe eventually this gets better, or it may be a limitation of this type of scan.
But I’ve talked with many doctors who say that MRI just isn’t actionable enough due to the limitation of imaging.
But for our purposes, full body MRI scans, done without a specific cause, are net harmful and should be avoided.
I mean, it’s legal and people can spend their money on whatever they like. But people spend money on all sorts of unproven “health” expenses. I don’t think MRI scans are as bad as homeopathy, but it’s in that same area.
This, of course, is different from diagnostic scans. MRIs are valuable tools and it’s not the scan is bad, just how they are used sometimes.
So a potential problem is that they are too low resolution? and that is something specific of full body MRI scans?
I still disagree with the "net harmful" argument if it relies on patient's psychology. People may overreact at first out of ignorance, but we learn to stop worrying after being generally exposed to a new thing
Agreed, I think people imagine these scans are a magic Star Trek tricorder. These aren't magic machines that diagnose exact things precisely. Most of the time you're looking to diagnose something you already know about, different situation and different uses altogether.
It’s funny how people seem to assume that information is perfect and it’s just about discovery. And people trust numbers even if they don’t know the veracity.
I remember people reading Covid case counts and taking shifts as having meaning at the local level that just doesn’t exist. A shift of cases from 50 to 100 and back to 50 over two weeks is much more likely to just be a reporting backup than some one week spike. The data quality especially in small areas is so variable it’s not actionable. But people would watch as if it mattered.
There’s some things like temperature that are accurately measurable, but most things have a lot of context that only lets you know how to use things.
I know if I could get a report on my body that said something like:
Death by heart disease
- 50% chance by age 65
- 99% chance by age 87
Death by cancer
- 50% chance by age 67
- 99% chance by age 78
Death by stroke
- 50% chance by age 73
- 99% chance by age 92
... and so on, and it was fairly accurate: It would make me a nervous wreck for the rest of my life. Nothing good would come of this knowledge. Maybe I'd exercise more.
This is absolutely true of many personality types! But not others. (And there are perhaps some marginal temperaments that could, with more practice & supporting culture, become more sanguine about any worrying-but-non-terminal interim/probabilistic estimates.)
So, rather than denying the info from those who could use it without becoming a 'nervous wreck', maybe the optimal policy would be to offer it based on a psychological pre-screen?
You cannot pre-screen for whether or not someone will be affected by receiving a report that they are 68% likely to die by heart disease in the future. That's illogical and quite frankly insane.
Of course you can. It's not a unique tendency uncorrelated with all other aspects of personality/temperament/anxiety. There are expecially emotional people, especially neurotic people, especially gloomy people – and their opposites, who remain cold in the same situations that freak others out. And it's largely, though not perfectly, predictable.
Many people will have enough of a self-conception – like the author of the post to which I replied – that they will have a fairly accurate idea of how they'll react.
Any many "in the middle" might, by considering, rehearsing, & precommitting to moods/strategies beforehand, helpfully prep/prime themselves to more-calmly handle whatever probabilistic results come back.
Those too concerned, by their own self-knowledge or that of experts/pretests, can skip the risk of "knowing too much" via an elective test, while others can proceed, knowing the risks, with informed consent.
The artificially rationed – & frankly abusive – traditions for training & licensing doctors in the US makes me heavily discount "the general opinion among doctors" as a guide to what's systemically-optimal.
They've been strongly filtered for obedience & conformity to a deeply-broken system.
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.
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.
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.
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.”
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.
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.
> 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.
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.)
While on vacation in Korea I received a full work up (MRI, blood labs, echo, CT scan, dental work, etc) for a couple thousand dollars. I wanted to do it because I wanted a clear picture of my health. I get headaches a lot and have expressed concerned to doctors in the USA but they never seemed to care. I honestly wanted the MRI to rule out anything bad.
Was it worth? I think so. The doctors ended up seeing something on my thyroid which was then biopsied. It came back benign but something to keep an eye on and check every six months or so. This carried back over to the USA.
So you 1. paid a couple thousand dollars, 2. got a biopsy 3. it was nothing 4. probably are going to get a biopsy in the future because you wan to "keep an eye on it".
Where you are, will you actually get access to the Data? Or will they just review and store it for you? Just interested in the output and what you actually get to keep.
As I understand it in the US you legally have access to the data as it's part of your medical records.
In my experience it's as simple as asking, they give you a CD-R containing some DICOM files and a freeware DICOM viewer. Maybe more modern health systems will let you just download the files.
If they are paying for it out of pocket, I assume they would have the option for the raw data. Maybe a small-ish processing fee, because...American healthcare.
Doctors will tell you don’t do this: waste of time, more harm than good, etc.
This is all fine as general advice when you see patients as mere statistics and you want to apply broad generally applicable advice for everyone.
However, it is more meaningful for the wealthier individual or a VIP to have their body fully documented. Even if no action is taken for some possible tumors, having some knowledge is better than being totally blind. And maybe it’s a waste of money, but if you have the money to waste it’s not a big deal.
Some knowledge actually ISN'T always better than none. Imagine you get a scan and find an aneurysm. The aneurysm has a 1/100 chance of rupturing during your life. Surgery is too risky for the relatively small chance of rupture, so the advice is to "watch and wait". Now you have to go to bed every night wondering if tonight is the night that it ruptures and you don't wake up tomorrow. We know that psychological distress exacts a physical toll on the body. So, on net, assuming no rupture, you gained nothing except the harms associated with knowing about the aneurysm, or the harms associated with unnecessary treatment for a low risk condition. This is the case with all kinds of diseases across the board.
The stress is temporary. Eventually, you come to terms: You will die and there will be nothing you can do about it. So be grateful for everyday, and take nothing for granted. Then, you will know peace.
What's funny is that I recall reading an article 30 years ago about rich Japanese forming clubs to purchase MRI access for regular scans. It stuck with me because I thought "someday, we'll all get annual MRIs for baseline data. But now 30 years in the future it still not happening. Because we suck at preventative medicine.
We don't yet know that. Point me at a study showing health outcomes from a cohort study where one group gets full-body MRIs every 3 months compared to a control group that does not.
I'd like to see a "back of the envelope" analysis of how many MRI scanners would be needed to make this universal, and in particular how much helium we'd need. I'd guess it would be challenging, but the scale might be good for spurring advances in AI (edit, I had meant to say advances in MRI).
MRI is good at some things, but is often inferior to CT for other issues. You basically can't MRI the heart, but CT scanners are so fast that you can scan the heart.
A typical spine MRI that includes cervical, thoracic, and lumbar takes around 2 hours. A full body CT takes a minute or two even with older machines. So purely logistically, regular scans will be CT, with MRI only used for certain issues (they do well with soft tissue like ligament injuries).
I must have AI on the brain, I actually meant to say MRI, as in advances in scanner technology. But of course you're right it would be a very rich source of data
I don't see anything unnecessary about getting full body scans, especially if one has a family history of a given disease or aliment.
If I'm predisposed for ________, and I find out really early, to the point where I might be able to fight (some of) it with lifestyle changes, why not?
Why not? Because of the well known, widely understood problem of iatrogenic harms. Your conclusion does not follow from your premise. If you have a predisposition to a particular disease, get screened FOR THAT specific thing. Getting a full body scan just opens you up to unnecessary psychological distress, unnecessary treatments, and unnecessary healthcare costs for many things which would have never affected you in the slightest had you avoided getting a full body scan. Do you REALLY want to know that you have an aneurysm that only has a 1/100 chance of rupturing, when you would've otherwise gone your entire life without ever worrying about whether tonight will be the night that it ruptures and you won't wake up tomorrow? Do you really want to know that you have a slow growing cancer that would only affect you when you're already less 12 months from your ultimate death at age 92, but instead you got invasive life-altering surgery at age 65 because it just happened to show up on a scan? If we had instant, easy cures for every disease, then yes, get a full body scan - unfortunately this just isn't the case, and the harms greatly outweigh the benefits.
The full body scan would be part of the problem, because it's not always clear what medicine should do given a specific finding on a scan, and decisions made on the basis of the scan would then lead to potential harms, as I outlined above. Why advocate for scans that would cause net harm?
If an MRI scan is truly practically harmless, and its only consequence is the information you get from it, then it's not the MRI who is causing the harm, but our own response to it
"Avoiding MRI scans" as a solution is a hack, you are trapped in a local minima solving the problem very indirectly. I may be willing to accept it as a temporarily pragmatic solution because solving our medical system may be very hard and bureaucratic
But, according to your arguments, the real problem then would be how we react to the results of a scan. Whether it is how patients react to them, or how the medical system reacts.
If full-body scan only informs, then do not kill the messenger!
I had significant resistance to getting a leg bone length scan from my GP despite explaining this was purely to inform a decision to fit one sided lifts to my rowing shoes.
Luckily the practice has a run-on field doctor for one of the local sporting codes who agreed it was low risk of harm and potentially useful. My physio at the gym noticed postural issues some time ago under load.
I'm told by an E.P. that almost everyone has some leg length variance, and it's "normal" -and rarely matters. My partner has hypermobile joints, and in her case gait issues meant getting an asymmetric lift helped her enormously.
Now, I can sit straighter in the 4 on the water, I can do more legwork on a pilates reformer, I have the choice to get differential height orthodics. I'm not going to do anything quickly because I have no visible gait problems or pain, it's purely biomechanics under load rowing for me.
Tl;DR some diagnostic scans are worth it outside of illness.
What happens when profits corrupt the healthcare system. Body scans and yearly checkups don't work because they're healthcare theater primarily set to sell reassurance. We should be spending money on money-saving prophylaxis of common, treatable diseases like CHD and screening all body systems for function and decline. PAC and CT angios lack evidence but they're the obvious tools to assess coronary artery state before there's a problem, rather than waiting until a patient has a heart attack and dies.
As a doctor organising a scan is the path of least resistance, patients almost universally think that a scan = good care, and why would they not? More data is better surely as another commentator has noted.
So we do the scan and find an ovarian cyst, not to be unexpected, the prevalence of an ovarian cyst is widely quoted as anywhere between 8-15% [1]. You tell the patient that you found an ovarian cyst. Naturally she asks if it’s concerning. It’s a simple cyst, so if we use [1] to inform our figures we can tell her that in 1 years time there’s a 50% chance that the cyst will be gone, a 34% chance it will still be there, a 7.5% chance that there will be more than one cyst and a 5.5% chance that there will be a complex cyst. Simple cysts are not thought to be linked with an increased risk of ovarian cancer, but complex ones are.
Now on hearing that there’s a 5.5% chance of finding a complex cyst next year the patient opts for follow up scanning. They of course Google symptoms of ovarian cancer and see that bloating is a symptom. The patient worries, she has very bothersome bloating, she reads about doctors missing ovarian cancer and worries if her cyst has been misdiagnosed. Of course 31% of the population have bloating of significance [2], but how do we know in this case it isn’t ovarian cancer? So she gets an early ultrasound 3 months later. The cyst has now gone from the ovary, but the other ovary now has a cyst. She gets another scan in 3 months time and the cyst is still there, she’s finds herself more and more worried, why didn’t it go like the last cyst? She reads online about a blood test for ovarian cancer, the CA125. She reads survivors stories telling her the importance of having this blood test done early, so she goes to the doctor and asks to have it done. It comes back slightly elevated. Her fear is confirmed, she has cancer. Now a raised CA-125 has a positive prediction rate of about 10%, and with her imaging findings the likelihood is likely lower, but it is not zero. So we proceed to biopsy. A couple of weeks later the result is in, no cancer, in keeping with the most likely outcome in the scenario. The patient elated at the news thanks the doctor and all is well. Her journey has been 6 months all in all, she’s had multiple sleepless nights, her blood pressure has gone up and her stress levels have been higher, slightly invisibly nudging her up risk of a stroke or other cardiovascular disease in the future.
Now is this good medicine? I guess that’s up for debate, and like I said at the beginning patients like when we scan them, and appreciate when we tell them that their biopsy is negative. They like seeing things done. The doctor who told her not to the scan was clearly a hack as it showed the cyst. Despite the fact that if she’d listened to them she’d have saved herself months of worry and ultimately her health would have probably been slightly better through having avoided the stress and an invasive biopsy. We also know that screening for ovarian cancer does not change mortality for ovarian cancer, it leads to 1% of all women screened having some form or surgery who do not end up having cancer and 3-15% of these women end up with a major complication from this surgery. [6]
Another statistic that I keep in mind is that 11.5% of people under 40 have a thyroid cancer at autopsy and 13.4% of people over 80 [5]. These people lived a good chunk of their lives with this cancer which never caused them any issues or harm, it lay there growing slowly completely undetected and then they died of something else. Now would these people have been better off if they’d got a whole body scan, picked up the cancer and spent the last year of their life having their thyroid gland removed, taking new medication to replace their thyroid hormone, having regular bloods and follow up, all for something that ultimately never would have caused them issues, again I’m not convinced. The patient themselves however if we did go down that route will come in and thank me for saving their life, they’re often so grateful and happy that the cancer was picked up, sometimes they come in with a complication from the surgery, their voice horse from the vocal cord palsy, but they don’t mind as their cancer has been cured. The cancer that would never have caused them any harm.
You should also take into account patients that are already worried, and how much peace it brings when the scan results come clean
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But I am really worried with a deeper issue.
A full-body MRI scan provides information, and supposedly with no harm (at least physically)
According to your arguments, the medical system doesn't currently know what to do with it to provide an overall benefit (Allow me to be skeptical, but let's roll with it)
So your attitude is to not collect the information in the first place. I assume you are thinking that because there are no immediate benefits and lots of cost
But I'm sure there are, at least, future benefits. Why not instead start learning from this new source of information to do good in the future?, like at least, collect it for future references / comparisons with future scans
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If you still think the benefits do not compensate the cost, then fine, that's a completely personal decision that should not be imposed to others.
Doctor's role is to communicate as accurately as possible the benefits/harm of an action, and let patients decide for themselves if the cost is worth it or not
The root of the issue seems to be that general scans are simply not that informative unless problems are very obvious or couched with other symptoms. If they can't tell the difference between a benign lump and a tumor without additional information then they don't actually serve a useful purpose. Garbage data is useless, after all.
Using them in a targeted manner because the patient is reporting symptoms or somesuch appears to be a different use case. The signal to noise ratio of an untargeted scan is otherwise too high to be of much value determining treatment.
This should be the top rated comment. It’s not a purely statistical problem as some other comments say. The problem is that the follow up tests carry health risks to the patient.
The counterarguments presented in the article are silly. Of course we should have full body scans for preventative purposes. Could you imagine a utopian society where we don’t regularly have full body scans to detect problems early? Any new problems that arise as a result of this trend should be handled as exactly that — new problems.
Too many false positives leading to wasted time and costs? Raise the price for the supplemental scans and improve detection precision and recall. Unnecessary procedures that make a benign situation worse? That’s a sign to improve medical research in that area. Too much demand for MRI machines pulling away time from patients that need to use them? Build more MRI machines. This is one of those situations where the ideal end goal seems obvious, and I think we should just plow ahead and address new problems as they arise. In the long run, better preventative medicine will save time, costs, and minimize suffering for everyone. A few road bumps along the way shouldn’t dissuade us from even getting started, otherwise we never will.
No medical intervention is without risk. Any drug or surgical intervention has the risk of negative side effects which must be weighed against the benefits of the intervention. Medical research won’t make surgeries much less risky than they are, even highly targeted laparoscopic procedures have risks. Cutting deep into you tissues is just inherently risky. Drugs too, even the safest drugs will have very negative outcomes for some number of people.
That you think this is a trivial problem shows that you’re largely ignorant of some 30 years of research and clinical debate.
no but an mri scan and blood tests are pretty damned close
30 years of research and clinical debate have largely come to the wrong conclusion because medical doctors are, by and large, mathematically illiterate; in some countries, like the usa, they are also strongly motivated by cya, which comes into direct conflict with the patient's well-being in cases like this
MRI scans and blood tests are, but what comes next? If they find something there's always a least a follow-up biopsy, and often times what's seen on the screen would have never impacted the person's life. Yes, there are outliers, but if you do enough scans you are guaranteed to find something wrong with you that you would never have known about otherwise.
if the mri scans and blood tests show strong enough evidence of a problem that will impact your life that the risk outweighs the risk of the follow-up biopsy, you should get the biopsy
if they don't you shouldn't
so either you're better off or you're no worse off
unless you have to be dealing with a doctor in cya mode
I have some familiarity with diagnostic imaging - a lot of the time with these scans there's enough to say "yes, there is something there you should definitely get checked out" but you can't make a full assessment without a biopsy. The MRI is going to find things you need to investigate further.
It'll also reveal a bunch of stuff you didn't need to know. Do you want to know about that minor slipped disc in your back that wasn't bothering you before? The nocebo effect is very real.
if investigating it further isn't worth the risk, you don't need to investigate further
if investigating it further is worth the risk, then it's a good thing you did the scan
this superstitious ideology that ignorance is good for you has always been popular; what's surprising is that some people still hold to it despite the industrial and scientific revolutions
knowing about the minor slipped disc in your back might be important information if it starts hurting; you'll know it isn't a metastatic bone cancer. you might also be well advised to avoid taking up olympic weightlifting
> if investigating it further isn't worth the risk, you don't need to investigate further
How do you make that call? What do you, as an eager but uneducated layman, use to decide that? You now know there's a heterogeneous cyst in your abdomen that the doctor says is super unlikely to be cancerous but it's not impossible that it could be. How do you evaluate your odds? Are you opting for the biopsy? If there's a dozen of such cysts in all corners of your body? Again, the MRI is a tool to help spot a problem, it's not going to give you the diagnosis.
> What do you, as an eager but uneducated layman, use to decide that?
Is this a trick question? I use my doctor's expertise and advice, obviously. Just like I do for any other nontrivial medical question.
This has happened to me a number of times throughout my life. I have some problem, my doctor requests a scan (or x-ray or ultrasound or...), it turns up some anomalies, and my doctor has to evaluate them to decide if they are relevant to anything. For many of them the answer is, no, they're not. Now I know that I have a cyst here and some slightly misaligned vertebræ there and ... that's fine. They weren't causing the problem I had and they're probably not causing any other problems either.
The argument that we must not look at ourselves because if we do, we'll be compelled by some mysterious force to take dangerous interventions is silly and just seems like an excuse for medical incompetence or laziness.
> You now know there's a heterogeneous cyst in your abdomen that the doctor says is super unlikely to be cancerous but it's not impossible that it could be.
That's up to the individual to decide - blanketing people in ignorance and leaving it up to chance should not be the only option.
But you're still making decisions out of ignorance and you're biased towards worst case outcomes because it's you. People are going to make the choice out of fear and that will lead to a ton of extra procedures and those people possibly having a worse quality of life as a consequence of all the elective procedures.
I would say you're biased because it's not you. You've turned everybody into a statistic to make your decisions based on the idea that it's more important to keep your percentages in line with expectations created in a broken health care environment where reactionary medicine is preferred over preventative medicine.
How are we supposed to ever make progress here if that's your mindset? This is the medical system that fears its own incompetence so much that it would prefer to NOT have data. How silly is that? What other industry operates this way?
Can you imagine an engineer doing maintenance on a plane and saying "hey actually, we have no idea what we are doing so it's better if we don't do an inspection so we don't mess it up even more by trying to fix something that might not be a problem."
usually i read the wikipedia articles about the disease and the common treatments, a couple dozen papers starting from google scholar via pubmed and sci-hub, maybe a relevant medical textbook via libgen. also talk to family members and friends about the issue. you can also find papers in medical journals and the mmwr on the prevalence of possible complications from different kinds of biopsies
this takes a little longer than undergoing the biopsy, but it's enormously more pleasant, and it lets you know when doctors are ignorant or lying, which is perhaps even more important information. it's orders of magnitude easier than undergoing chemo and radiation so i don't know why 'eager but uneducated' laypeople don't always do it. maybe they're too used to living in a world without sci-hub and libgen
it's also easier when it's not the first time
it's never impossible that any part of your body could be cancerous, so 'super unlikely to be cancerous but it's not impossible that it could be' is a terrible justification for taking action
> it's never impossible that any part of your body could be cancerous, so 'super unlikely to be cancerous but it's not impossible that it could be' is a terrible justification for taking action
If you knew that you or your spouse had something that could be an issue but was unlikely to be - and it's nearly guaranteed that somewhere in your body right now you have stuff that would come back as "possibly a problem" in imaging - you'd be comfortable not taking action? I doubt that's how most people would response.
This is actually a bit subtle. For example I've heard more than one radiologist claim that if you look carefully, literally anyone's body scan will contain details that could justify work up.
The fact is, if you do this broadly in a population and you work up everything you see that would justify it, some small number of people will die or suffer serious problems from complications of follow up.
This is a fundamental problem in screening technologies (of any kind) with imperfect sensitivity. You can't get away from this, so you try and be clear that the net benefit is (much) higher.
I'm not even against the idea of baseline scans, but the idea that this part is simple is naive.
Or it's because the problem is genuinely hard. See above ('imperfect sensitivity')... the same problem exists in e.g. blood tests.
I'm no radiologist but I've seen enough of this done that I'd lean that way. Especially if you consider realistic bounds on time and additional information.
In the abstract more information is always better. In practical healthcare with real constraints, sometimes it makes things worse globally for reason above.
Think about say a diagnostic blood test with a poor sensitivity (but better than chance) on a very rare disease. As an oversimplification: for a bound take your population * workup rate * fatality rate due to workup and you have a baseline needless death due to the screening (NB there is basically always a fatality rate). The number you are comparing to is lives saved due to earlier detection.
Better than chance means it's strictly more information always. But as policy, you shouldn't do it unless you can be extremely confident that lives saves is much larger than lives lost due to the process.
This is a bit counter intuitive, but it is a fundamental issue in a lot of healthcare policy. The real calculations are more complex but in the end it is unavoidably actuarial in nature.
this is not a global optimization problem; it's a local optimization problem. one person is deciding whether or not to spend their own money on an mri, or a blood test or whatever, on themself. they are the ones in the best position to do that, and for very-low-risk tests like mris it is very rare that the optimal decision is for a rich person not to get them
another nuance is that you don't have to be extremely confident that the mri or biopsy or whatever will increase your expected daly or qaly or whatever; in the cases where you're not extremely confident, it's because it doesn't matter much either way, because you're weighing two extremely small risks against each other. if you make the wrong decision and lose (in expectation, risk-adjusted) a hundredth of a qaly to a blood test or an extremely unlikely cancer, it wasn't a terrible decision, just a small mistake
(even if that small mistake kills you in three months)
the cases where the decision matters, it's easy to get enough information to be extremely confident
Well I did say the actual calculations would be (and are) more complicated. And as I said, short of availability constraints, the MRI itself isn't an issue, it's the follow up.
Ignoring the fact that in the real world due to constraints this isn't really a local optimization, if we assume infinite availability you still have a problem that low sensitivity tests lead to excess unnecessary work up risks. Your assertion that it is always easy to get good information leading to correct choices here is just incorrect and probably naive.
The trade offs you are talking about are very well known and have been studied by professionals for decades; none of them will claim it easy - for good reasons.
Note I'm not appealing to authority here. Many people can educate themselves to the degree that in a narrow area of their own healthcare they are as or more knowledgable than the average professional. However, this is not at all easy, and will require a ton of work. The cost benefit for a lot of screening etc. just isn't there; for a particularly symptomatic disease it may well be.
What are you talking about? There’s a huge body of public health literature about the dangers of for example doing too many colonoscopies on people below a certain age.
This isn’t a controversial claim at all among people familiar with stats on outcomes across large populations. It’s tricky to get right and your glib dismissal comes across as arrogant and ignorant.
The idea that you believe that the entire public health establishment on 3 continents is wrong about the risk of preventative scans is ridiculous. Surely you. have some evidence to support your heterodox position. It can't be that "doctors are innumerate," because I assure you that many aren't, and there are statisticians that work in public health.
How do you propose the medical field determines which small tumors will become life threatening in general? Can you beat the best research hospitals in this task? Even an average oncologist?
i already explained my reasoning above; it's obviously correct, and it doesn't depend on my knowledge about which small tumors will become life-threatening, so it sounds like you didn't understand it
you can calculate the cost and expected morbidity due to any particular candidate test (mri, blood panel, biopsy, ct, pet, whatever) and compare it against the reduced expected morbidity due to the probably-not-present disease, using whatever metric of morbidity you like best (ypll, daly, expected change in your malpractice insurance premiums, whatever), using whatever risk tolerance you like best
for mris and blood panels obviously this will favor doing the test in almost all cases, unless traveling to the hospital is a significant hardship or the money is enough to be important to you
for other tests it may not, and watchful waiting is often a better choice than doing further tests
with a little work, you can always beat the best research hospitals at this task because you care about different things than they do. this is not the same thing as beating them at guessing whether your prostate is going to kill you before something else does
I totally agree with you. This idea that “there is no problem if we don’t look for one” is absurd. We have plenty of statistical techniques to prevent unnecessary surgeries for every anomaly in an MRI scan; let’s utilize those instead of keeping medicine in the dark ages.
> That you think this is a trivial problem shows that you’re largely ignorant of some 30 years of research and clinical debate.
Am I not allowed to criticize decades of research on astrology because I haven’t paid any attention to it?
If 30 years of research and clinical debate have led to this situation where you get 5 different opinions from 5 different doctors, then maybe it’s time to kick out the incumbents and replace them with people who adhere a little better to the scientific method. I would rather trust my medical care to a group of particle physicists who had one year to study medicine than the 30 year experts who can’t reproduce any of each others’ work and seem ignorant of any advances in statistics or inference over the same period of time.
> That you think this is a trivial problem shows that you’re largely ignorant of some 30 years of research and clinical debate.
Biologists are still doing punch card-level stuff. If we started cloning monoclonal, antigen-free bodies in massive body farms and performing head transplants, that'd solve almost every non-cranial disease. I could see that becoming a preventative solution to aging, too. Renewed cardiovascular health, clean lungs, thymus, etc.
But it is. Giant body farms of clones raised without the benefit of a womb that we then decapitate and reattach our heads to is a non-trivial enterprise.
I believe they're saying that this type of comprehensive early detection leads to subsequent interventions on issues that would never develop into anything serious where they left alone. by increasing the number of interventions happening you could actually be making the patient worse off
The problem is that you don't know which ones would never develop into anything if left alone.
The reason they're left alone now is that you don't know they're there, because you never do any test that shows them being there.
But once you do a test that shows that something is there, it's a lot harder to just leave it alone. Something is there, and you don't know that it's never going to be a problem, so you end up not leaving it alone.
If you were going to leave the thing alone anyway regardless of what the first test showed, there's no point in doing the first test at all.
On an individual level, lets assume a polyp in the colon, there's no way to know which may become individually cancerous and which will remain small and benign. The genes are the same, the size and appearance may be the same. You can't know.
At a population level its well established that beyond a certain point you're injuring more people than you are helping by doing the colonoscopies at all. Where to draw that line is where the debate is playing out. The problem is well known, and I'm not aware of ANYONE seriously suggesting that it's possible to eliminate this problem.
If the MRI finds a dozen indicators in your body in a bunch of different locations that might be cancer, all with different likelihoods where would you draw the line on getting them biopsied? Would you be comfortable having heterogeneous masses in your body that have a minor chance of being cancer? Because the MRI is going to say "might be", not "is".
At least in the US, that's not how the healthcare system works. Some blame CYA. Some blame the fact that the system only makes money per procedure. The GP is saying in the US, patients often get procedures that are not worth the risk.
No, I'm saying that anywhere in the world you might get an unnecessary procedure. It is impossible to know in many cases if small tumors will become malignant, so judgement calls must be made. Finding more of them inevitably leads to more unnecessary procedures across a population. This is well established in European and American public health literature. This is why screening guidelines exist.
After getting another answer from them further below in this thread, I am under the impression that they are not entirely forthright about what it is they are claiming, or not claiming.
It is well established that more MRI lead to more procedures that are ultimately themselves risky and useless. This is extremely difficult to parse out on an individual level but obvious in the data at a population level.
Colonoscopies are a great example. As their use increases past a threshold more people are injured by additional surgery than you actually help. This is again at a population level.
Beyond a certain point all scans will produce more unnecessary procedures than beneficial ones. It's the nature of treating illnesses with uncertain presentations. Everyone has lots of odd bits and small benign tumors that are harmless. But these often look indistinguishable from the early stages of something serious. Even biopsy isn't without risk.
Again, for the people in the back: There's no such thing as minor surgery.
Every surgical procedure carries a real risk, which amortizes over the population of billions of people into thousands to millions of complications and deaths. That's the cost, and an intervention has to be good enough to justify that cost. Vaccines are good enough for that. Some types of cancer screening is good enough for that. Popping yourself in a full-body scan for a fishing expedition? Almost certainly not.
The result of this product is that a few more very rich people will die a bit sooner than they would have otherwise. Whether or not you think that's an upside is up to you and your personal politics.
I think that long term, preventative scans do make sense. With that preface, I don't think we should just argue there are no problems, and it's all easily solvable.
"Too many false positives leading to wasted time and costs? Raise the costs for the supplemental scans and improve detection precision and recall."
You can't improve precision/signal on an inherently weak and noisy signal. There are many things showing up on MRIs that currently require a biopsy. You need alternative DX routes to disambiguate, MRI alone can't do that. As for raising the costs - who pays? Medical costs are already completely bonkers.
"That’s a sign to improve medical research in that area. "
We know we need to improve search. We don't need to cause negative outcomes to reinforce that signal.
"Too much demand for MRI machines pulling away time from patients that need to use them? Build more MRI machines. "
Again, who pays?
"we should just plow ahead and address new problems as they arise."
There is the problem of opportunity cost. Is that the best possible way to spend sparse resources? The medical community currently mostly thinks that it isn't.
Targeting wealthy people first does solve the "who pays" problem. It might make the "too few researchers" issue worse. It will cause a lot of unnecessary biopsies (because often that's the only alternative dx route) - but you could certainly lean into informed consent there. You do run the risk of poisoning MRIs as a diagnostic tool, because media will report any inconvenience to sufficiently wealthy people as a major problem.
All of this might be solvable, but "let's just press ahead and see" is a very bad approach here.
If the "things showing up on MRIs that currently require a biopsy" don't actually pass cost-benefit analysis on their own, that 'requirement' can & should be adjusted down. Or, new diagnostics with less cost/risk developed. That today's "MRI alone can't do it" isn't a hint what novel techniques might be able to do – once demand created.
A sufficiently-flexible & high-res set of downstream decisions can always choose to ignore data that isn't really helpful. Enough scans & experience might discover the new patterns.
Our ossified medical system, with those "already completely bonkers" costs, has a hard time adjusting, & sticks with habits & tech that's stale. Thus things the legacy system isn't ready to handle efficiently – novel diagnostics with floods of new data – get blamed.
But the only way out is through. Letting those with discretionary funds try speculative things is a way to improve faster than waiting for a burnt-out & bureaucratically-deformed "medical community" to rustle up the will/resources.
'If the "things showing up on MRIs that currently require a biopsy" don't actually pass cost-benefit analysis on their own,'
So if we can't tell if it's malignant or not, you're saying we should start cancer treatment just in case? It's not a question of "tech that's stale" or "an ossified system" - it's a question of not being able to tell all malignant and benign cells apart until you look at them under a microscope.
The last thing that space needs is a bunch of uninformed tech folks going "I don't know, let the market solve it, tech is great". I really recommend getting at least a basic education on the subject.
If it looks bad enough that you'd risk starting cancer treatment right away (!) with no further confirmation, it's definitionally something they'll have been glad to detect early.
But for most things, the advice would be: watch & maybe run some other tests, if cheap & low-risk, if and only if the preponderance of the data implies it's a net-gain.
If the MRIs become cheap enough, high-resolution enough, and the ML/stats-assisted classification becomes good enough – possible with more imaging/progression data – the most common thing might be: reimage in a month or two, compare results. Do more if and only if that calcs out for maximum welfare.
These are ultimately probabilistic equations, not things you can hand-wave off based on old anecdotes and mere hunches about what's net worthwhile, and what's not. You have to run the tests, run the numbers, and reach a data-driven answer.
On the other hand, people who don't trust the numbers, or their own ability to dispassionately follow the numbers if more data arrives, should absolutely be free to remain in blissful non-knowing.
Many people can – and many more with proper coachin should be able to – use new info only if it improves their welfare. They don't have to follow automated scripts from a less-informed era.
> There are many things showing up on MRIs that currently require a biopsy
they don't require a biopsy; you're still free to not get the biopsy after the mri
sometimes getting the biopsy is actually worse for you, on average, than the small chance that you'll have a very rare disease. probably in those cases you shouldn't get the biopsy, which means the mri didn't actually help you, but it didn't hurt you much either; you're US$650 poorer and worried, that's all
in other cases getting the biopsy is better for you, in which case the mri did help you
> Is that the best possible way to spend [scarce] resources?
fortunately, we have private property, so we already have a system for allocating scarce resources: their owner decides how to spend them. this turns out to work much better than the alternatives that have been tried, which routinely result in famines and genocides. so we don't need to come to a global community-wide consensus on that question; instead we can consider each case as it comes up
> they don't require a biopsy; you're still free to not get the biopsy after the mri
Have you ever talked through a scan with an oncologist? Or are you just reasoning in the abstract because you feel you can first-principle it?
Also, seriously, you want to turn this into a communism debate? fwiw, capitalism has already decided. The vast majority of resources goes to anything but full-body scans, because actual experts made the call what's more effective. Repeatedly. On many cases.
But you are right, you are of course free to make bad decisions with your money, and there will always be somebody happy to separate fools from their money. Capitalism does work.
I was thinking of this when a friend passed away from pancreatic cancer a couple of weeks ago. One of the reasons pancreatic cancer is so deadly is that it is deeply internal and symptoms of it are not present. This is true with all of the deadliest cancers. We already recommend colonoscopy to older adults which is a fairly invasive procedure to screen for colon cancer with no other history. If we could scan people with low or no ionizing radiation that would be a great tool.
A full body scan is a bit like p-hacking. If you have a hypothesis of what might be wrong and perform a specific test to see if some value is within normal range, there’s relatively little chance of a false positive.
If you test everything at the same time, some values are bound to be outside of the normal range, just because you’re measuring so many things at once. Doing any kind of procedure to further investigate or treat the symptoms has a risk associated with it.
In the end, doing a full body scan, with current medical technology (both in terms of the test equipment as well as our means to treat anything that comes up as a result of the test) is a risky thing to do. It sounds nice in theory, but unfortunately we do not live in the utopia you speak of.
It isn't just wasted time and costs, it's a risk beyond that.
If you scan any middle aged adult you will find abnormalities in their scan. In almost EVERY case those abnormalities will be benign, but once you've found them depending on risk factors a biopsy may be required. Almost all of those biopsies will also be negative, the tiny calcification in your lung or breast isn't a tumor. The swollen lymph node isn't a sign of lymphoma. A spot on a scan is FAR more likely to be down to habitus and scanning issues than some underlying medical issue.
But if you scan everyone, biopsy everyone, you're going to end up killing some of them too in addition to the waste of limited resources.
If you get the scan and do nothing, or you choose not to scan and do nothing, and it turns out to be something fatal, the outcome is the same: you die.
The difference, is if you do the scan, you might have an epiphany about your own mortality, and live your life truly savoring every moment, instead of being blindsided and quickly dying someday.
If you want preventive care. Exercise one more hour a week that what you are already doing. This actually reduces all-cause mortality. Anything else is snake oil. Including full body scans.
Well, yes, but all of that would need to be optimized for expected patient quality-of-life. If instead it'd be optimized to reduce risks as much as possible, we'd ultimately be spending all of our lives in medical facilities.
In non-utopian reality it'd be even worse, as the system would be optimized for shareholder value instead. Shareholders profit by scaring patients into believing they need to buy more medical interventions.
Maybe show a little sympathy? It only looks easy because it's not our problem to solve.
> Raise the price
Although raising a price does lower demand, a different price for a test doesn't make decision-making any easier. Predicting future costs and benefits (based on test results, not the test cost) is the hard part.
> a sign to improve medical research in that area
Decisions about whether to do a procedure assume current technology, not imagined future technology.
are you suggesting controlling the price as a centrally-planned public healthy policy, or that costs drive medical prices? in the US free market the price goes to administrative overhead and profit margins
