13 ms·

The madness of reduced medical diagnostics

87 points by dynm 4y ago

sudden_dystopia 4y ago
I have never understood this rationale to not do more comprehensive diagnostics. Sure, it costs more up front. But wouldn’t catching problems earlier save more money and suffering in the end?
- kayodelycaon 4y ago
  Because none of this happens in a vacuum. The tests aren’t perfect and open to interpretation, but that’s the least of the problems here. Sometimes no action is the correct action, but no one is going to do that. How many laws have been passed because “something needs to be done” even though nothing in the law needed fixing? Many people, I’d say most, are not happy with inaction. Knowing something may be seriously wrong can have an enormous emotional cost for some people. Dismissing this as irrational is like saying humans are irrational. (Spoiler: they are)
  - jjoonathan 4y ago
    Exactly, and the human "bias towards action" is amplified by legal mandate. A doctor can't recommend inaction if a pack of lawyers is lurking in the bushes waiting to pounce if the situation worsens.
  - dwelch 4y ago
    Agreed. I think the article and parent comment seem to be from the perspective of someone who has never had to, say, read or interpret a chest CT. Or had to tell someone that they have an indeterminate module that may be cancer but may be nothing. The article also seems to imply that their is one entity or person who controls all aspects of diagnosis (hence the meme at the top), from taking a history and doing a physical exam to perfectly understanding the intricacies of all additional diagnostic testing. Of course, your primary care doctor may not understand exactly what percentage of people in a low (or high) risk cohort with this lung nodule with certain specific imaging features turn out to have cancer. Hopefully the radiologist does—but they didn’t talk with the patient to assess their risk tolerance and data-collection preferences before saying “consider further evaluation with tissue sampling” in that report. At the end of the day, respecting patient autonomy matters. It sounds like whoever wrote this article would lean towards asking their doctor to collect as much information as possible. Others wouldn’t. In a perfect world, the patient will be well informed by their doctor, be well-counseled on the risks and benefits of a test / intervention, and will be capable of understanding things like statistics well enough to come to an informed decision that works for them. In reality, that often does not happen for a number of reasons.
- petercooper 4y ago
  I get a full MRI imaging every two years so I spent a lot of time researching the ethics around it just to be prepared, and there are two things I could bring up. First, false positives. There can be things that looks like problems but aren't, or that are problems but with complicated risk profiles around their management or resolution (especially true of aneurysms). For heavily studied situations where imaging is low risk and hugely effective with low false positive risk, most countries do have screening programs, such as regular cervical smears or mammograms for women of certain ages, as well as aortic aneurysm screening for men over 65 (in the UK, at least). Second, psychology. A surprising (to me) number of people do not want to know about their medical status until a problem actually occurs. But then once they do know, many folks can be prone to undue worry or hastily made emotionally driven decisions that run contrary to data. I'm going to totally make up these figures but as a demonstration of the idea, imagine that brain aneurysm scans tend to find aneurysms of concern in 5% of people and that of these 5%, 4% are likely to die within 5-10 years due to that aneurysm. Scan the entire country and you now have millions of people potentially terrified of an aneurysm that won't kill them. If an aneurysm is found and you are offered an operation with a 5% chance of mortality, are you taking it? The research I saw when I was looking into it is that, yes, most people want to get rid of the "problem", despite a higher risk of short term mortality rather than sitting it out. This is just one of the reasons doctors grimace when people want to get such scans without cause, but there are many others beyond the scope of this reply too.
  - SemanticStrengh 4y ago
    > Although cardiovascular disease is widely recognized as the leading cause of death, a lesser known fact is that aortic aneurysm is the 15th leading cause of death over the age of 65 years in the USA. I was not aware of this. non-surgical interventions: https://www.jstage.jst.go.jp/article/circj/advpub/0/advpub_CJ-13-1252/_article/-char/ja/ https://www.jstage.jst.go.jp/article/circj/advpub/0/advpub_C... > This is just one of the reasons doctors grimace when people want to get such scans without cause, but there are many others beyond the scope of this reply too. Great points. Is it legal for a doctor to hide informations to its patient? such as the fact he has a seemingly "minor" aneurysm ? > I get a full MRI imaging every two years You might wanna study radio-protectors such as NAC. I had read it is also a contrastive agent but it's unclear to me what it help to see and what it might inadvertently hide (if anything)
- incongruity 4y ago
  A number of reasons come to mind: 1. Not doing anything in the face of “evidence” is ripe for malpractice lawsuits, rightly or wrongly 2. Not doing anything in the face of “evidence” can drive anxiety for patients and many clinicians want to be seen as having some answer or path forward, however: 3. Not all diagnostics are risk or pain free 4. Not all diagnostics are precise enough to make treatment decisions clear, correct, and authoritative - so more diagnostics will lead to more false positives which, when paired with the previous points lead to trouble for the clinician and possibly the patient.
- ufo 4y ago
  That is one of those things that sound intuitively true, but isn't necessarily the case in practice. One example that I am more familiar with: thyroid nodules. Recently, the medical guidelines have increased the size threshold for a biopsy, where you poke a needle in it to find out whether it is cancer or not. We could assume that diagnosing these cancers when they are smaller would always better, but that is not the case... On one end, it turns out when the nodule really is cancer, it is just as safe to wait to do the biopsy only after it has grown over the size threshold. And on the other end, the biopsies are not 100% accurate. A good percentage of the time, it can't say conclusively whether it is cancer or not. When that happens the only way to know for sure is to surgically remove the thyroid, which might result in the patient being put on lifelong hormone medication. One might think that in a perfect world we would act rationally over this uncertain information and not remove the thyroid when all it has is a small nodule with uncertain diagnosis. However, human intuition doesn't work well with percentages. When a patient is told they have a chance of having cancer, no matter how small, they will want to pursue every avenue to investigate and resolve the matter, even when the cost benefit is not worth it. When they looked into the statistics of how many people were getting thyroid surgery we could see that as imaging technology improved, more and more people had thyroid surgery, with no reduction in the number of deaths from thyroid cancer.
- CogitoCogito 4y ago
  > Sure, it costs more up front. But wouldn’t catching problems earlier save more money and suffering in the end? No? That's even shown clearly in the anecdotes of the original blog post.
h2odragon 4y ago
If a test shows "narrowed arteries" or whatever but it's not currently impacting you; inaction is an option. Knew a fellow who was told he had a "weak blood vessel in his brain", had probably had it forever, but now he's retired they can "go in and fix it" and so he goes in for a surgery to remove a threat he was unaware of and that had not hurt him yet. He got out after a week, never really recovered, and died within 2 months. Apparently there was another aneurysm they failed to see or fix; because it couldn't have been a direct result of his procedure.
- SemanticStrengh 4y ago
  edit: my comment is not adequate for aneurysms Well there are solutions that have negligible risk of damage and potent likeliness of protection/improvement, e.g. for narrowed arteries the vasodilator tadalafil in low dose should be a net improvement. Then you might want to combine it with a pro-angiogenic drug such as VEGF or better BPC-137. Also even if someone seems asymptomatic it doesn't mean he is, narrowed arteries very likely to increase his aging rate and chances of death and are likely to create a nocitropic effect by creating a mini brain ischemia.
  - greggsy 4y ago
    While I’m sure you know what you’re talking about, and it is very interesting, it’s poor form to suggest treatments for a cardiovascular brain conditions, after being given second hand information of a single symptom with no further history or context.
    - SemanticStrengh 4y ago
      well yes I was talking in general, actually for brain aneurysms the recommendations I made are likely to increase mortality because the aneurysm has more likelihood to break with a vasodilated overflow.
- cma 4y ago
  Do you know the medical term for what he had? Was it one of these? https://en.m.wikipedia.org/wiki/Cerebral_arteriovenous_malformation https://en.m.wikipedia.org/wiki/Cerebral_arteriovenous_malfo...
rayiner 4y ago
> What? If the harms of the biopsy outweigh the benefits, don’t do the damn biopsy! But you’ll get sued if the scan suggests something but you don’t follow up and do the biopsy, and it turns out to be cancer. The author doesn’t seem to realize this is all happening against the background of potential litigation.
- adgjlsfhk1 4y ago
  Also, if you know that you won't do a biopsy even if the test comes back positive, then the screening isn't helping anyway.
  - ssivark 4y ago
    To paraphrase the author's point -- the doctor could have a policy to intervene only if the screening produces _flagrantly_ worrying results, and continue to not intervene in cases where the results are merely mildly worrying. Technically, this might lead to strictly better outcomes at the ensemble level. But any patient likely 1. doesn't care about ensemble performance 2. will get stressed out at the mildest indication of concern 3. induce a concave payoff for a trigger-shy doctor (no credit for correctly not intervening, and massive discredit for incorrectly not intervening).
xsor 4y ago
One reason behind why doctors can’t simply do tests then not follow up is simply medical malpractice suits. Often times, once you do the test you’re locked into figuring out everything even to the detriment of the patient for fear of getting your license revoked.
PaulKeeble 4y ago
The NHS has gone the other way and wont run diagnostic tests it really needs to. The end result is growing legal action over failure to diagnose conditions. Long covid is diagnosed in just 28,000 patients and yet the office for national statistics says by the symptom studies 1.8 million have it. There is no where I know of, certainly not on the NHS, where you can get a test for microclots, a condition found in the bulk of Long Covid cases and easily treatable but doesn't show up in normal clotting tests. You can get micro clot tests throughout a lot of Africa but such is the reluctance to run tests in the UK no labs have bothered. Its something we have known can be tested and treated for 17 months at least. Be careful about reducing the testing just because it drives over treatment because under treatment is quite deadly, cheaper maybe but also has a serious impact of life expectancy and disease burden. Life expectancy is dropping in the UK and disease burden is one of the highest in the western world and growing. The grass isn't greener on the low test and treatment side, health care is still increasingly expensive and the results are worse.
- refurb 4y ago
  But this is how population medicine works. You’re willing to trade off a few extra deaths if you can save a certain amount of money. Hell NICE in the UK put a very firm GBP figure on the value of a life-year. It works great at a population level since you maximize outcomes and keep costs low. But that isn’t that comforting when you’re the poor bloke who dies from lung cancer that could have been detected early but NICE said the 50GBP test isn’t cost-effective.
  - hammock 4y ago
    > But this is how population medicine works. You’re willing to trade off a few extra deaths if you can save a certain amount of money. Or even make a certain amount of money: https://www.openthebooks.com/substack-investigation-faucis-royalties-and-the-350-million-royalty-payment-stream-hidden-by-nih/ https://www.openthebooks.com/substack-investigation-faucis-r...
  - pfortuny 4y ago
    That is why population “medicine” is anything but “medicine”. The State is not a physician. But turns out that it IS.
mdrzn 4y ago
I am in a similar boat, I feel healthy but I would like to do a full body and blood checkup to know if there's anything coming down the line or if anything's out of order at the moment but I do not yet know. Is it better to know? To not know? To know when it's the moment? BTW I'm in Italy so it wouldn't even be that expensive to do every couple years.
- swayvil 4y ago
  You imply an interesting assertion. This machine will tell me how I feel better than I can do it myself. This secondhand abstraction is more reliable than my firsthand observation
edarchis 4y ago
That's all nice but we used to recommend systematic PSA screening for all males over 50. We later realized that there was a lot of false positives and that the intervention often brought more risks than it cured actual cancers. So it's only recommended for patients with risk factors. Now, consider the GP who has healthy 50yo, does a PSA anyway and it's positive. The GP could still decide not to act. But the patient is not so likely not to do anything. Or even understand the odds. At that point, if the patient dies, the GP is likely to get sued because he should have acted. Even if over all of his patients, not acting was more efficient. If the GP decides to act, however, regardless of whether the patient survives, he won't be blamed for it. So doctors have a nasty incentive to act.
a_c 4y ago
What about the other extreme, let everyone do all the tests imaginable? Or course it doesn't make sense. The balance is on how mych evidence available before a test is suggested. Evidence is the incident rate among the population and the false negative rate(specificity). I'm using very loosely defined terms here because I'm too lazy to quote the definition. But no need false dichotomy.
gumby 4y ago
There is an easy fix but nobody would stand for it: do full longitudinal surveillance of all tests. That is, the gent with the “narrowed” arteries could be followed to see if it becomes a problem (a lot of the metrics are, to simplify, fairly arbitrary and based on a small observational n). Perhaps he does have a stroke, perhaps not. Of course no one would stand for such an intrusive system. But over time it would improve diagnosis.
- SemanticStrengh 4y ago
  anonymised data about prescription correlations and symptom metrics is the #1 missed opportunity of mankind progress. The tragic fact is, for most drug we have zero clue what they're doing to your body after a 6month-1 year period, nor do we know what do the combinatorial explosion of polypharmacical interactions do. There are people currently living the dream of increased lifepsan/healspan by getting lucky on that pharmacological lottery ticket and other (most) are living the invisible damage nightmare.
- cryoz 4y ago
  > the gent with the “narrowed” arteries could be followed How exactly would you follow? Stress testing, angiography, cardiac MR, CCTA??
  - gumby 4y ago
    No, just basic outcome. If the data were collected someone could look to see if people with narrowed cerebral arteries suffered, say, more strokes. If such a correlation were found, more intervention would indicated, if not, then not. It’s a pretty slow process, but outcome is what really matters, and even if slow it would be faster than doing nothing.
gumby 4y ago
There’s a baseline issue here which is insurance companies and actuaries. If you can afford to be outside the insurance system in the US you can get excellent care. That can include having tests done that aren’t covered by insurance and avoiding tests that an insurance company would normally require just for CYA reasons, but aren’t worth the risk. But the incentives of the insurance-driven care are not aligned with optimal patient outcome.
- SemanticStrengh 4y ago
  in countries that have public paid medicare (such as France) it really shows that it leads to a strong lag in adopting modern medical practices and drugs. I'm not advocating against free medecine, however this limitation should be more highlighted than it currently is. Too many people think they're getting the best treatment..
  - pfortuny 4y ago
    Same here in Spain “the best medical service in the world” (as all piliticians boast, from left to right and back again).
    - SemanticStrengh 4y ago
      Make medecine great again /s
  - gumby 4y ago
    That kind of lag is not always a good thing. I'm OK with medicine not being an early adopter domain.
    - SemanticStrengh 4y ago
      The patient should have a right to be an early adopter if he wants to. Besides, drugs will never leave alpha status if we never let them flow on the market. Although yes obviously a gradually titrated A/B testing scheme would be much more reasonable than the current illegal/legal shift. Moreover cf my other comments, anonymised statistics are needed.
SemanticStrengh 4y ago
More generally I had read on HN a while ago that this is the reason why doctors don't do a Full-body radiography/scan. Because many humans have bugs/anomalies that are mild/non-issues but are ambiguous and anxiety prone. The latter (and most salient reason tragically) is that the doctos by covering much more data, would become legally responsible for not seeing (e.g. a tumor found in a place that wasn't the tissue/region target of the original investigation) I find those really sad and I want to have a whole body radio (and disclose that I take the anxiety cost willfully and that I abandon my right to sue the doctor for this specific radio), is it possible? Is there a place where this can be done?
- thaeli 4y ago
  In the US, many "concierge" doctors (the ones who don't take insurance) will order this type of scan if you want it.
  - SemanticStrengh 4y ago
    I wasn't aware, how does that even work, radio machines can fit a whole body field of view? Thx I'm in EU unfortunately.
    - JumpCrisscross 4y ago
      > how does that even work It’s just a full-body MRI. Costs a couple thousand dollars. Would put it in the category of neat curiosity and possibly useful as a baseline or if you have surprise cancer or something. But totally unnecessary and to be avoided if you’re prone to medical anxiety.
      - SemanticStrengh 4y ago
        > Costs a couple thousand dollars Why such scaling with the size? Pure greed? The guy has mostly to push a button..
        4y ago
maxfan8 4y ago
One slightly reasonable common argument I hear for reduced medical diagnostics is: “we don’t have the resources; it’d overwhelm the medical system”. While this may be the case for some tests, there are probably a great number of tests that could be scaled to be done yearly on the whole population.
- CogitoCogito 4y ago
  > While this may be the case for some tests, there are probably a great number of tests that could be scaled to be done yearly on the whole population. Isn't this already the case? Tests that are considered worth doing regularly even without extra symptoms are done regularly. E.g. mammograms and colonoscopies/stool tests. (I'm ignoring your focus on "yearly" since really you care about "regularly" given that yearly is totally arbitrary and timing that makes sense is clearly dependent on the tests in question.)
  - maxfan8 4y ago
    No. Not all screenings/tests are done, even when it's super low cost and non-invasive. For example, one factor that is used to determine whether to screen for certain types of cancer is "Possible harms from follow-up procedures". [1] Another factor that is taken into account it the chances of a false positive. [1] Both of these factors are irrational, since more information is strictly optimal given a rational agent. They should not even merit consideration in choosing whether to undertake a screening (this information should only be used after a screening is done, to determine follow-up action). In my opinion, the only justifiable factors are probably along the lines of: - invasiveness (e.g. if it's non-invasive or minimal cost) - benefit to the patient if detected - cost relative to other screenings/actions that can be done for the patient Everything else seems strictly suboptimal. [1]: https://en.wikipedia.org/wiki/Cancer_screening#Risks https://en.wikipedia.org/wiki/Cancer_screening#Risks
    - CogitoCogito 4y ago
      > For example, one factor that is used to determine whether to screen for certain types of cancer is "Possible harms from follow-up procedures". [1] Another factor that is taken into account it the chances of a false positive. [1] Both of these factors are irrational, since more information is strictly optimal given a rational agent. Your entire argument here seems to require patients to be rational agents. They aren't.
aaron695 4y ago
IG_Semmelweiss 4y ago
Incentives have a powerful effect in healthcare: - Physicians want to avoid getting sued - Physicians want to get paid , just like everyone else. - The payor in the system is not the patient, but a faraway entity removed from the situation on the ground. In such instances, all 3 factors influence a decision. If a decision to perform procedure X is close to 50/50 (test/no test) Do you think "no test" will win ? Now put that in the macro context of millions of patient visits. now, since we are talking diagnostic testing, you may need to be tested at a hospital. So now, you are voluntarily exposing yourself to a hub of tired doctors/bureaucracy/germs. That starts looking like madness , for sure
cflyingdutchman 4y ago
I was squarely in the author's camp and am now a little less so having seen the impact of false positives on my family. Anxiety is real and harmful, and humans are generally very bad at responding to tiny, explicit risk of big harm (small nodule in lung that may be cancer or not, covid, vaccine side-effects, shark attacks).
- deleted 4y ago
  [deleted]
mreiner 4y ago
From what I understood about how the system works in most European countries: A test has a specific sensitivity and a rate of false positives. So for screening (CT in this case) you would want a high sensitivity and low cost, while the false positives would not be your priority. The positives should go through a confirming test (biopsy in this case) with a high specificity. Here cost and sensitivity are usually secondary. Now insurers look at the screening tests rate of false positives. If they deem it too high, they don't want doctors to do those tests on a population with a low probability of having the condition you are screening for (low base rate). If the patient belongs to a subgroup shown to have a high enough base rate of a condition, then it makes sense to do the screening. Then you have different patients, some want to get one MRI each year, some only want to run diagnostic after they experience symptoms. I believe most doctors respect that individual risk tolerance within the given framework. Now the thresholds obviously should be revised regularly as cost, test properties and even base rates of diseases change, but I don't see a systemic defect here, my blind spot?
IG_Semmelweiss 4y ago
The big problem with testing is that it assumes the human body can be averaged. We are not. One person's natural lump is another's cancer. One person's low heart rate is another's natural genetic gift. Modern medicine , particularly compensation, wants to put everything in neat black/white boxes. Which is why tests are more dangerous than they seem. You are not average, and you shouldn't compare yourself to any perceived average because the human body is not average. You should compare yourself to you, and that's all the doctor should use.
tylerrobinson 4y ago
> And I’ll wearily pretend to accept that people are emotional and couldn’t understand Bayesian reasoning or false positives and so we need to worry about stressing them out (#2). > Why are we taking as given that a net-negative decision to do a biopsy will be made The author should stop wearily pretending that anxiety isn’t a common result of a positive test, and recognize that the average person is not comforted by a Bayesian analysis when their health could be at risk. If continuing to a biopsy is as common as the author says (I don’t have any data on it), that suggests anxiety IS a common response and we can’t simply wish it weren’t the case. Mental health is health.
- pfortuny 4y ago
  Thanks for saying this. There was an article the other day here on HN about someone totally obsessed with “fulfilling“ his iphone app’s health “objectives”. Anxiety is one of the worst outcomes of over-diagnostics.
- DeathArrow 4y ago
  But the best way to proceed is still to make the CT and let the patient decide.
- jchw 4y ago
  This. I don’t want to know there’s a nodule and then hear “but it could be nothing. Don’t worry about it.” Because then suddenly, I’ll become hyper aware of every potentially significant symptom and have to resist the urge to constantly google and check if there’s a chance it might indicate something. Is that pimple a pimple? Hey, I don’t remember my neck feeling this lumpy. Boy, I sure do seem to have sinus issues a lot. Are these joint aches normal? Etc, etc, etc. As a kid, I felt absolutely invulnerable to worrying about my health. The first time I experienced true health anxiety is when my doctor pointed out a mole on my back and said “do you want to check this mole for cancer?” to which I replied, “oh, I guess so?”… only he didn’t. Because he checked with insurance, and insurance came back negative on it. I am still in my 20s. I’m not in the best health, but my everyday life is pretty uninhibited by health issues. I don’t wake up with coldsweats. So yeah, it could happen to me, but frankly it’s worth being skeptical at my age. But when the doctor pointed out that mole, they shattered the mental barrier I had between myself and cancer patients. I knew mentally that of course it could happen to me, but I had absolutely no idea that the signs of it could literally be hiding on my back, and I would be none the wiser. I googled and I learned a whole lot, and my intuitions were very wrong. In fact, I had many symptoms that can indicate various cancers. I heard stories about pimples that were not pimples, back pain that was not back pain, etc. people living normal lives who just went in for a checkup and suddenly faced certain death. I’ve mostly snapped out of the hypochondria mindset, but still today I wonder about some symptoms in a way I never would’ve before. My life is altered by this one thing a doctor said off hand. And for what it’s worth, I’m not saying he should not have done that. Insurance should’ve covered the biopsy just in case. I’ve outright noticed that sometimes, doctors will slightly edit your responses to things to get insurance to OK a diagnostic, and I think it’s in some part because they know that if you don’t get that peace of mind it could be damaging. Being hyper aware of your heart beat or super concerned about sleep apnea is not as bad as suffering from actual disease, but it’s certainly it’s own kind of hell. It’s weird to me because much like cancer patients, I viewed myself as separate from hypochondriacs and immune to it as a whole. A lesson learned the hard way, and now I feel a twinge every time I see a new headline about cancer or hypochondria.
cryoz 4y ago
Why do the CT scan in the first place if you are not going to do a biopsy if you find something?
psyc 4y ago
Not for the reasons central to the article, but my favorite is the No HPV Test For Men stance. Because men usually don't have symptoms and have far less risk of cancer than women..... Just take 10 seconds to ponder how myopic that is. But that's how the medical establishment thinks about health care.
OrvalWintermute 4y ago
This article is rather funny because it misses out on key facts of how doctors practice medicine these days. I listen to my supremely well educated plastic surgeon wife regularly discussing and giving guidance to office staff around patients in their private practice. Their general approach is to get patient statistics, and that is all, without the aggregated vital signs. I asked her once, "Why don't you get the patient vital signs too?" Her response was unexpected, "If we get patient vital signs, we immediately become liable for patient overall health. Our malpractice insurance is specific to the practice of medicine for plastic surgeons, and plastic surgeons only. Our front office staff are normally front office only, or aspiring doctors on a break between their undergrad and entry to medschool. Our practice uses no Nurse Practicioners, Physician's Assistants, or nurses. We're not set up, or staffed appropriately to deliver general medical care." Conclusion 1: Medical care is characterized by liability control; there are logistics/staffing aspects to medicine around specific types of care. Medical Diagnosis we think of as scans, remote tests. You get a CAT scan, you get an MRI, or X-ray, bam, 15 seconds, 5 minutes, or an hour later (after waiting in a hospital for hours) you're done and some radiologist or other specialist is interpreting the results and you have a diagnosis. That is true in some cases, but not others. If you get a positive mammogram, or a suspicious lump what is the next step? Welp, that is regularly one of two things - a needle biopsy, or an investigational biopsy. Needle implies small, thin, fairly painless. Not this needle - instead imagine a needle designed for tissue harvesting, like a horse sized needle. This big giant thing needs to go into your breast to suck up enough of the suspicious lump for a pathologist to examine it. Alternatively, you could have an investigational biopsy where a surgeon takes a small amount of tissue from inside your breast with a scalpel. Investigational biopsies via scalpel can be a big scam too, where a car accident occurs, a cut tendon in the hand, and the surgeon decides to open up the arm past the wrist to visualize all the soft tissue up the arm. Lucrative billing enhancements.. But, when it comes to breasts, we know that certain life changes predispose towards a positive mammogram for a limited time window. Stopping breast feeding being the foremost change that can cause suspicious lumps. Conclusion 2: Diagnostic tests can be quite painful, and, at the wrong time, quite unneeded. Some of them are damaging. Good medicine is about as much when to intervene, and when to test, just as much as it is about when not to intervene and when not to test.
- 4y ago
teekert 4y ago
This is so true. And I think we need more Bayesian models in Hospital IT systems to help with this. The probability needs to be updated, you shift to a new population with new evidence. It seems so clear, yet somehow it is so intuitive. Why? In many respects, Bayesian reasoning is just what we do, but then sometimes it fails us. We are just not good at accepting risks of any kind I think. Better to not put ourselves into this position seems to be the reasoning. Avoid that "The test told you so!" feeling...
norswap 4y ago
> If you do a CT scan and it shows a mass, you’ll order a biopsy. > But because that patient was low-risk, the harms of that biopsy will outweigh the benefits. > Thus, you shouldn’t do the CT scan. > What? If the harms of the biopsy outweigh the benefits, don’t do the damn biopsy! I'm not sure what the point of doing the CT scan if we're not going to act on its result. Sure, you gain the confidence that everything's gucci if it turns negative. Is that really worth the stress of the test going positive and the not doing the biopsy? Seems dubious to me.
- gpt5 4y ago
  The author is not arguing against efficiency in the medical system, but against the reasoning of - “if we test for X bad things will happen”
- j-pb 4y ago
  In a "perfect world" we'd all get routine checks, this would have two advantages: * Most illneses are easier to treat and have better long term outcomes in terms of morbidity, when they are detected early / in a asymptomatic stage. * We could collectively use the data collected from scanning "healthy" people, and adjust our bayesian priors so that we can more accurately adjust our diagnostic measures. E.g. common virus infections can give you brain lesions visible in MRI scans. However since MRIs are expensive we rarely scan healthy people so every lesion in an MRI is an immediate supicion of MS or other neurodegnerative diseases. We simply don't have good baselines for this. The latter would allow us to look at all the indicators more holistically to make a well balanced judgement if more invasive diagnostics are warranted.
the_sleaze9 4y ago
I think the author is correct in the acedemic sense, but ignorant of the reality of healthcare. If a doctor receives a test result that shows a suspicious mass, then neglects to order a biopsy to investigate further, there are 2 rough outcomes. 1. It was nothing 2. It was cancer If it turns out to be (2), the doctor and the practice/hospital/whatever gets sued for malpractice. On a more ranty note, why does everyone think they are better at other people's jobs than those people are? Where is the basic trust in the other? You think a doctor in the United States after ~15 years of school doesn't know that most biopsies turn out to be more harmful that useful? Come on. Restore some basic trust in other's competence.
- axg11 4y ago
  This is the reality. In fact, the situation is getting even more complicated as direct-to-consumer screening becomes more popular (e.g. full body MRI scans). Companies that are selling the health screenings are only incentivized to sell as many screenings as possible. Scans inevitably result in benign incidental findings far more often than they identify real health problems. Then the patient is directed to a specialist who is uninvolved with the screening company. The specialist is incentivized to aggressively investigate the finding out of fear of malpractice and due to pressure from the patient. Nobody has ever thanked their doctor for inaction. The end result far too often is a series of expensive and painful procedures with a large dose of anxiety. Of course screenings also save lives, but nobody is responsible for ensuring the benefits outweigh the harms at the macro level. I don't think any actor in that chain is malicious, it's just an example of poorly aligned incentives. Screening companies, doctors and patients all believe they are making the most optimal choice.
- peteradio 4y ago
  Presumably the patient can decline the biopsy? What happens to liability in that case? Does the doctor then have to decline to work with that patient further? What happens to liability if the doctor doesn't fire the patient? I agree there needs to be trust somehow, yet it seems practitioners hands are tied from a level above to toe the line for liability reasons rather than patient outcome. Is a doctor able to take into account all extenuating circumstances of a patient or only those predefined on a checklist passed on by a murky review process? What happens to patients who do research and find alternative (maybe better) opinions, well are they in network? Can a network have differing opinions among its practitioners?
bell-cot 4y ago
Amusing Idea: Let people apply for "Always Full Diagnostics" status, and accept ~0.01% of the population. The "lucky" AFD's would get every test, scan, biopsy, follow-up, exploratory surgery, etc. that was remotely plausible. The anonymized results from all those (mostly unwise) things would be a gold mine of public health data. And I suspect there'd be more than enough obvious adverse outcomes to convince most of the other ~99.99% that "more is better" does not apply to medical diagnostics.
qgin 4y ago
We're in an uncanny valley in medicine right now where it is good enough to give the impression that we have more control over human health than we actually do. More and more, the general public has come to see medicine as the Genius Bar service department for the human body. Everything that can be fixed, should be fixed. Let's get this thing back to like-new condition as we can, right? But in reality, medicine is still much closer to the older model of simply seeking to reduce human suffering. You will die of something one day and most likely you will have 8 other things wrong with you when it happens. Curing all cancer in all humans would only at about 2 years of average increased lifespan because of all the other causes of death that are creeping up right behind it in the background. So there is a tension here of what medicine should conceptually be doing. If, in the effort to "fix everything" (which is impossible), you actually introduce more suffering (by treating a diagnostic finding that may never have resulted in symptomatic disease), then many would say that's a failure of medicine.
daveguy 4y ago
This entire argument of it being "madness" hinges on the fact that a rational actor will know they are part of a low risk demographic and while they might worry, they won't seek medical care when they are informed they are low risk and "it's probably nothing". This is not a reasonable assumption. I'm not sure if the author has ever had a biopsy, but most people will seek out care if they get some concerning result, like a nodule on the lungs that's "probably benign because of your priors." Maybe you could opt in to "I am fully rational and will only make decisions using bayesian statistics with accurate priors." Maybe you could hide test results or generate false results based on probabilities as not to steer someone into an unnecessary procedure. (Yes this it tongue in cheek) Those who really really want to do that next test because they want the information are free to do that. But it seems like the exact mentality that will make you more prone to a botched biopsy. If you keep following the trail of more information you will get to a test that may not be best for your health outcome. That may be the initial x-ray. It seems that if you have not-fully-rational human beings and an obligation to truthfully inform them of the results of medical tests, then maybe not doing the test to begin with has significantly better health outcomes. Can you not chain bayesian probabilities?
lobocinza 4y ago
That's why I avoid reading stock market news during bear periods.
dataangel 4y ago
I think this article misses that there is a statistical conditioning issue. If the research literature says that patients who get scans showing lumps in their lungs have X% chance of having lung cancer, there is an implicit conditioning there in the patient having complained to the doctor of some kind of symptom that prompted the scan. X% isn't the probability of having cancer given lump on scan, it's the probability of having cancer given a lump on a scan in patients have breathing trouble. If you test too much you run the risk of there not being data about what the baseline is! Studies for a lung cancer treatment usually take 1000 random people and give them all lung x-rays and then wait to see how many get cancer later and survive the experimental treatment, instead they usually find 1000 people already diagnosed with lung cancer that had it diagnosed by traditional means (e.g. scans prompted by breathing problems). The same reasoning applies to deciding whether to do a biopsy -- most biopsies are going to be prompted by scans from a relevant patient complaint, so statistics computed to determine the risk/benefit tradeoff are implicitly conditioned on that. You need a separate study to determine the risk/benefit for incidental discovery.
chrismeller 4y ago
I’ve been shocked at the night and day attitude between the US and Estonia. The US definitely over-tests and Estonia just waits to see if you die and they don’t have to worry about it.

87 points by dynm 4y ago

I have never understood this rationale to not do more comprehensive diagnostics. Sure, it costs more up front. But wouldn’t catching problems earlier save more money and suffering in the end?

kayodelycaon 4y ago
Because none of this happens in a vacuum. The tests aren’t perfect and open to interpretation, but that’s the least of the problems here. Sometimes no action is the correct action, but no one is going to do that. How many laws have been passed because “something needs to be done” even though nothing in the law needed fixing? Many people, I’d say most, are not happy with inaction. Knowing something may be seriously wrong can have an enormous emotional cost for some people. Dismissing this as irrational is like saying humans are irrational. (Spoiler: they are)
- jjoonathan 4y ago
  Exactly, and the human "bias towards action" is amplified by legal mandate. A doctor can't recommend inaction if a pack of lawyers is lurking in the bushes waiting to pounce if the situation worsens.
- dwelch 4y ago
  Agreed. I think the article and parent comment seem to be from the perspective of someone who has never had to, say, read or interpret a chest CT. Or had to tell someone that they have an indeterminate module that may be cancer but may be nothing. The article also seems to imply that their is one entity or person who controls all aspects of diagnosis (hence the meme at the top), from taking a history and doing a physical exam to perfectly understanding the intricacies of all additional diagnostic testing. Of course, your primary care doctor may not understand exactly what percentage of people in a low (or high) risk cohort with this lung nodule with certain specific imaging features turn out to have cancer. Hopefully the radiologist does—but they didn’t talk with the patient to assess their risk tolerance and data-collection preferences before saying “consider further evaluation with tissue sampling” in that report. At the end of the day, respecting patient autonomy matters. It sounds like whoever wrote this article would lean towards asking their doctor to collect as much information as possible. Others wouldn’t. In a perfect world, the patient will be well informed by their doctor, be well-counseled on the risks and benefits of a test / intervention, and will be capable of understanding things like statistics well enough to come to an informed decision that works for them. In reality, that often does not happen for a number of reasons.
petercooper 4y ago
I get a full MRI imaging every two years so I spent a lot of time researching the ethics around it just to be prepared, and there are two things I could bring up. First, false positives. There can be things that looks like problems but aren't, or that are problems but with complicated risk profiles around their management or resolution (especially true of aneurysms). For heavily studied situations where imaging is low risk and hugely effective with low false positive risk, most countries do have screening programs, such as regular cervical smears or mammograms for women of certain ages, as well as aortic aneurysm screening for men over 65 (in the UK, at least). Second, psychology. A surprising (to me) number of people do not want to know about their medical status until a problem actually occurs. But then once they do know, many folks can be prone to undue worry or hastily made emotionally driven decisions that run contrary to data. I'm going to totally make up these figures but as a demonstration of the idea, imagine that brain aneurysm scans tend to find aneurysms of concern in 5% of people and that of these 5%, 4% are likely to die within 5-10 years due to that aneurysm. Scan the entire country and you now have millions of people potentially terrified of an aneurysm that won't kill them. If an aneurysm is found and you are offered an operation with a 5% chance of mortality, are you taking it? The research I saw when I was looking into it is that, yes, most people want to get rid of the "problem", despite a higher risk of short term mortality rather than sitting it out. This is just one of the reasons doctors grimace when people want to get such scans without cause, but there are many others beyond the scope of this reply too.
- SemanticStrengh 4y ago
  > Although cardiovascular disease is widely recognized as the leading cause of death, a lesser known fact is that aortic aneurysm is the 15th leading cause of death over the age of 65 years in the USA. I was not aware of this. non-surgical interventions: https://www.jstage.jst.go.jp/article/circj/advpub/0/advpub_CJ-13-1252/_article/-char/ja/ https://www.jstage.jst.go.jp/article/circj/advpub/0/advpub_C... > This is just one of the reasons doctors grimace when people want to get such scans without cause, but there are many others beyond the scope of this reply too. Great points. Is it legal for a doctor to hide informations to its patient? such as the fact he has a seemingly "minor" aneurysm ? > I get a full MRI imaging every two years You might wanna study radio-protectors such as NAC. I had read it is also a contrastive agent but it's unclear to me what it help to see and what it might inadvertently hide (if anything)
incongruity 4y ago
A number of reasons come to mind: 1. Not doing anything in the face of “evidence” is ripe for malpractice lawsuits, rightly or wrongly 2. Not doing anything in the face of “evidence” can drive anxiety for patients and many clinicians want to be seen as having some answer or path forward, however: 3. Not all diagnostics are risk or pain free 4. Not all diagnostics are precise enough to make treatment decisions clear, correct, and authoritative - so more diagnostics will lead to more false positives which, when paired with the previous points lead to trouble for the clinician and possibly the patient.
ufo 4y ago
That is one of those things that sound intuitively true, but isn't necessarily the case in practice. One example that I am more familiar with: thyroid nodules. Recently, the medical guidelines have increased the size threshold for a biopsy, where you poke a needle in it to find out whether it is cancer or not. We could assume that diagnosing these cancers when they are smaller would always better, but that is not the case... On one end, it turns out when the nodule really is cancer, it is just as safe to wait to do the biopsy only after it has grown over the size threshold. And on the other end, the biopsies are not 100% accurate. A good percentage of the time, it can't say conclusively whether it is cancer or not. When that happens the only way to know for sure is to surgically remove the thyroid, which might result in the patient being put on lifelong hormone medication. One might think that in a perfect world we would act rationally over this uncertain information and not remove the thyroid when all it has is a small nodule with uncertain diagnosis. However, human intuition doesn't work well with percentages. When a patient is told they have a chance of having cancer, no matter how small, they will want to pursue every avenue to investigate and resolve the matter, even when the cost benefit is not worth it. When they looked into the statistics of how many people were getting thyroid surgery we could see that as imaging technology improved, more and more people had thyroid surgery, with no reduction in the number of deaths from thyroid cancer.
CogitoCogito 4y ago
> Sure, it costs more up front. But wouldn’t catching problems earlier save more money and suffering in the end? No? That's even shown clearly in the anecdotes of the original blog post.

h2odragon 4y ago

If a test shows "narrowed arteries" or whatever but it's not currently impacting you; inaction is an option. Knew a fellow who was told he had a "weak blood vessel in his brain", had probably had it forever, but now he's retired they can "go in and fix it" and so he goes in for a surgery to remove a threat he was unaware of and that had not hurt him yet. He got out after a week, never really recovered, and died within 2 months. Apparently there was another aneurysm they failed to see or fix; because it couldn't have been a direct result of his procedure.

SemanticStrengh 4y ago
edit: my comment is not adequate for aneurysms Well there are solutions that have negligible risk of damage and potent likeliness of protection/improvement, e.g. for narrowed arteries the vasodilator tadalafil in low dose should be a net improvement. Then you might want to combine it with a pro-angiogenic drug such as VEGF or better BPC-137. Also even if someone seems asymptomatic it doesn't mean he is, narrowed arteries very likely to increase his aging rate and chances of death and are likely to create a nocitropic effect by creating a mini brain ischemia.
- greggsy 4y ago
  While I’m sure you know what you’re talking about, and it is very interesting, it’s poor form to suggest treatments for a cardiovascular brain conditions, after being given second hand information of a single symptom with no further history or context.
  - SemanticStrengh 4y ago
    well yes I was talking in general, actually for brain aneurysms the recommendations I made are likely to increase mortality because the aneurysm has more likelihood to break with a vasodilated overflow.
cma 4y ago
Do you know the medical term for what he had? Was it one of these? https://en.m.wikipedia.org/wiki/Cerebral_arteriovenous_malformation https://en.m.wikipedia.org/wiki/Cerebral_arteriovenous_malfo...

rayiner 4y ago

> What? If the harms of the biopsy outweigh the benefits, don’t do the damn biopsy! But you’ll get sued if the scan suggests something but you don’t follow up and do the biopsy, and it turns out to be cancer. The author doesn’t seem to realize this is all happening against the background of potential litigation.

adgjlsfhk1 4y ago
Also, if you know that you won't do a biopsy even if the test comes back positive, then the screening isn't helping anyway.
- ssivark 4y ago
  To paraphrase the author's point -- the doctor could have a policy to intervene only if the screening produces _flagrantly_ worrying results, and continue to not intervene in cases where the results are merely mildly worrying. Technically, this might lead to strictly better outcomes at the ensemble level. But any patient likely 1. doesn't care about ensemble performance 2. will get stressed out at the mildest indication of concern 3. induce a concave payoff for a trigger-shy doctor (no credit for correctly not intervening, and massive discredit for incorrectly not intervening).

xsor 4y ago

One reason behind why doctors can’t simply do tests then not follow up is simply medical malpractice suits. Often times, once you do the test you’re locked into figuring out everything even to the detriment of the patient for fear of getting your license revoked.

PaulKeeble 4y ago

The NHS has gone the other way and wont run diagnostic tests it really needs to. The end result is growing legal action over failure to diagnose conditions. Long covid is diagnosed in just 28,000 patients and yet the office for national statistics says by the symptom studies 1.8 million have it. There is no where I know of, certainly not on the NHS, where you can get a test for microclots, a condition found in the bulk of Long Covid cases and easily treatable but doesn't show up in normal clotting tests. You can get micro clot tests throughout a lot of Africa but such is the reluctance to run tests in the UK no labs have bothered. Its something we have known can be tested and treated for 17 months at least. Be careful about reducing the testing just because it drives over treatment because under treatment is quite deadly, cheaper maybe but also has a serious impact of life expectancy and disease burden. Life expectancy is dropping in the UK and disease burden is one of the highest in the western world and growing. The grass isn't greener on the low test and treatment side, health care is still increasingly expensive and the results are worse.

refurb 4y ago
But this is how population medicine works. You’re willing to trade off a few extra deaths if you can save a certain amount of money. Hell NICE in the UK put a very firm GBP figure on the value of a life-year. It works great at a population level since you maximize outcomes and keep costs low. But that isn’t that comforting when you’re the poor bloke who dies from lung cancer that could have been detected early but NICE said the 50GBP test isn’t cost-effective.
- hammock 4y ago
  > But this is how population medicine works. You’re willing to trade off a few extra deaths if you can save a certain amount of money. Or even make a certain amount of money: https://www.openthebooks.com/substack-investigation-faucis-royalties-and-the-350-million-royalty-payment-stream-hidden-by-nih/ https://www.openthebooks.com/substack-investigation-faucis-r...
- pfortuny 4y ago
  That is why population “medicine” is anything but “medicine”. The State is not a physician. But turns out that it IS.

mdrzn 4y ago

I am in a similar boat, I feel healthy but I would like to do a full body and blood checkup to know if there's anything coming down the line or if anything's out of order at the moment but I do not yet know. Is it better to know? To not know? To know when it's the moment? BTW I'm in Italy so it wouldn't even be that expensive to do every couple years.

swayvil 4y ago
You imply an interesting assertion. This machine will tell me how I feel better than I can do it myself. This secondhand abstraction is more reliable than my firsthand observation

edarchis 4y ago

That's all nice but we used to recommend systematic PSA screening for all males over 50. We later realized that there was a lot of false positives and that the intervention often brought more risks than it cured actual cancers. So it's only recommended for patients with risk factors. Now, consider the GP who has healthy 50yo, does a PSA anyway and it's positive. The GP could still decide not to act. But the patient is not so likely not to do anything. Or even understand the odds. At that point, if the patient dies, the GP is likely to get sued because he should have acted. Even if over all of his patients, not acting was more efficient. If the GP decides to act, however, regardless of whether the patient survives, he won't be blamed for it. So doctors have a nasty incentive to act.

a_c 4y ago

What about the other extreme, let everyone do all the tests imaginable? Or course it doesn't make sense. The balance is on how mych evidence available before a test is suggested. Evidence is the incident rate among the population and the false negative rate(specificity). I'm using very loosely defined terms here because I'm too lazy to quote the definition. But no need false dichotomy.

gumby 4y ago

There is an easy fix but nobody would stand for it: do full longitudinal surveillance of all tests. That is, the gent with the “narrowed” arteries could be followed to see if it becomes a problem (a lot of the metrics are, to simplify, fairly arbitrary and based on a small observational n). Perhaps he does have a stroke, perhaps not. Of course no one would stand for such an intrusive system. But over time it would improve diagnosis.

SemanticStrengh 4y ago
anonymised data about prescription correlations and symptom metrics is the #1 missed opportunity of mankind progress. The tragic fact is, for most drug we have zero clue what they're doing to your body after a 6month-1 year period, nor do we know what do the combinatorial explosion of polypharmacical interactions do. There are people currently living the dream of increased lifepsan/healspan by getting lucky on that pharmacological lottery ticket and other (most) are living the invisible damage nightmare.
cryoz 4y ago
> the gent with the “narrowed” arteries could be followed How exactly would you follow? Stress testing, angiography, cardiac MR, CCTA??
- gumby 4y ago
  No, just basic outcome. If the data were collected someone could look to see if people with narrowed cerebral arteries suffered, say, more strokes. If such a correlation were found, more intervention would indicated, if not, then not. It’s a pretty slow process, but outcome is what really matters, and even if slow it would be faster than doing nothing.

gumby 4y ago

There’s a baseline issue here which is insurance companies and actuaries. If you can afford to be outside the insurance system in the US you can get excellent care. That can include having tests done that aren’t covered by insurance and avoiding tests that an insurance company would normally require just for CYA reasons, but aren’t worth the risk. But the incentives of the insurance-driven care are not aligned with optimal patient outcome.

SemanticStrengh 4y ago
in countries that have public paid medicare (such as France) it really shows that it leads to a strong lag in adopting modern medical practices and drugs. I'm not advocating against free medecine, however this limitation should be more highlighted than it currently is. Too many people think they're getting the best treatment..
- pfortuny 4y ago
  Same here in Spain “the best medical service in the world” (as all piliticians boast, from left to right and back again).
  - SemanticStrengh 4y ago
    Make medecine great again /s
- gumby 4y ago
  That kind of lag is not always a good thing. I'm OK with medicine not being an early adopter domain.
  - SemanticStrengh 4y ago
    The patient should have a right to be an early adopter if he wants to. Besides, drugs will never leave alpha status if we never let them flow on the market. Although yes obviously a gradually titrated A/B testing scheme would be much more reasonable than the current illegal/legal shift. Moreover cf my other comments, anonymised statistics are needed.

SemanticStrengh 4y ago

More generally I had read on HN a while ago that this is the reason why doctors don't do a Full-body radiography/scan. Because many humans have bugs/anomalies that are mild/non-issues but are ambiguous and anxiety prone. The latter (and most salient reason tragically) is that the doctos by covering much more data, would become legally responsible for not seeing (e.g. a tumor found in a place that wasn't the tissue/region target of the original investigation) I find those really sad and I want to have a whole body radio (and disclose that I take the anxiety cost willfully and that I abandon my right to sue the doctor for this specific radio), is it possible? Is there a place where this can be done?

thaeli 4y ago
In the US, many "concierge" doctors (the ones who don't take insurance) will order this type of scan if you want it.
- SemanticStrengh 4y ago
  I wasn't aware, how does that even work, radio machines can fit a whole body field of view? Thx I'm in EU unfortunately.
  - JumpCrisscross 4y ago
    > how does that even work It’s just a full-body MRI. Costs a couple thousand dollars. Would put it in the category of neat curiosity and possibly useful as a baseline or if you have surprise cancer or something. But totally unnecessary and to be avoided if you’re prone to medical anxiety.
    - SemanticStrengh 4y ago
      > Costs a couple thousand dollars Why such scaling with the size? Pure greed? The guy has mostly to push a button..
      - 4y ago

maxfan8 4y ago

One slightly reasonable common argument I hear for reduced medical diagnostics is: “we don’t have the resources; it’d overwhelm the medical system”. While this may be the case for some tests, there are probably a great number of tests that could be scaled to be done yearly on the whole population.

CogitoCogito 4y ago
> While this may be the case for some tests, there are probably a great number of tests that could be scaled to be done yearly on the whole population. Isn't this already the case? Tests that are considered worth doing regularly even without extra symptoms are done regularly. E.g. mammograms and colonoscopies/stool tests. (I'm ignoring your focus on "yearly" since really you care about "regularly" given that yearly is totally arbitrary and timing that makes sense is clearly dependent on the tests in question.)
- maxfan8 4y ago
  No. Not all screenings/tests are done, even when it's super low cost and non-invasive. For example, one factor that is used to determine whether to screen for certain types of cancer is "Possible harms from follow-up procedures". [1] Another factor that is taken into account it the chances of a false positive. [1] Both of these factors are irrational, since more information is strictly optimal given a rational agent. They should not even merit consideration in choosing whether to undertake a screening (this information should only be used after a screening is done, to determine follow-up action). In my opinion, the only justifiable factors are probably along the lines of: - invasiveness (e.g. if it's non-invasive or minimal cost) - benefit to the patient if detected - cost relative to other screenings/actions that can be done for the patient Everything else seems strictly suboptimal. [1]: https://en.wikipedia.org/wiki/Cancer_screening#Risks https://en.wikipedia.org/wiki/Cancer_screening#Risks
  - CogitoCogito 4y ago
    > For example, one factor that is used to determine whether to screen for certain types of cancer is "Possible harms from follow-up procedures". [1] Another factor that is taken into account it the chances of a false positive. [1] Both of these factors are irrational, since more information is strictly optimal given a rational agent. Your entire argument here seems to require patients to be rational agents. They aren't.

aaron695 4y ago

IG_Semmelweiss 4y ago

Incentives have a powerful effect in healthcare: - Physicians want to avoid getting sued - Physicians want to get paid , just like everyone else. - The payor in the system is not the patient, but a faraway entity removed from the situation on the ground. In such instances, all 3 factors influence a decision. If a decision to perform procedure X is close to 50/50 (test/no test) Do you think "no test" will win ? Now put that in the macro context of millions of patient visits. now, since we are talking diagnostic testing, you may need to be tested at a hospital. So now, you are voluntarily exposing yourself to a hub of tired doctors/bureaucracy/germs. That starts looking like madness , for sure

cflyingdutchman 4y ago

I was squarely in the author's camp and am now a little less so having seen the impact of false positives on my family. Anxiety is real and harmful, and humans are generally very bad at responding to tiny, explicit risk of big harm (small nodule in lung that may be cancer or not, covid, vaccine side-effects, shark attacks).

deleted 4y ago
[deleted]

mreiner 4y ago

From what I understood about how the system works in most European countries: A test has a specific sensitivity and a rate of false positives. So for screening (CT in this case) you would want a high sensitivity and low cost, while the false positives would not be your priority. The positives should go through a confirming test (biopsy in this case) with a high specificity. Here cost and sensitivity are usually secondary. Now insurers look at the screening tests rate of false positives. If they deem it too high, they don't want doctors to do those tests on a population with a low probability of having the condition you are screening for (low base rate). If the patient belongs to a subgroup shown to have a high enough base rate of a condition, then it makes sense to do the screening. Then you have different patients, some want to get one MRI each year, some only want to run diagnostic after they experience symptoms. I believe most doctors respect that individual risk tolerance within the given framework. Now the thresholds obviously should be revised regularly as cost, test properties and even base rates of diseases change, but I don't see a systemic defect here, my blind spot?

IG_Semmelweiss 4y ago

The big problem with testing is that it assumes the human body can be averaged. We are not. One person's natural lump is another's cancer. One person's low heart rate is another's natural genetic gift. Modern medicine , particularly compensation, wants to put everything in neat black/white boxes. Which is why tests are more dangerous than they seem. You are not average, and you shouldn't compare yourself to any perceived average because the human body is not average. You should compare yourself to you, and that's all the doctor should use.

tylerrobinson 4y ago

> And I’ll wearily pretend to accept that people are emotional and couldn’t understand Bayesian reasoning or false positives and so we need to worry about stressing them out (#2). > Why are we taking as given that a net-negative decision to do a biopsy will be made The author should stop wearily pretending that anxiety isn’t a common result of a positive test, and recognize that the average person is not comforted by a Bayesian analysis when their health could be at risk. If continuing to a biopsy is as common as the author says (I don’t have any data on it), that suggests anxiety IS a common response and we can’t simply wish it weren’t the case. Mental health is health.

pfortuny 4y ago
Thanks for saying this. There was an article the other day here on HN about someone totally obsessed with “fulfilling“ his iphone app’s health “objectives”. Anxiety is one of the worst outcomes of over-diagnostics.
DeathArrow 4y ago
But the best way to proceed is still to make the CT and let the patient decide.
jchw 4y ago
This. I don’t want to know there’s a nodule and then hear “but it could be nothing. Don’t worry about it.” Because then suddenly, I’ll become hyper aware of every potentially significant symptom and have to resist the urge to constantly google and check if there’s a chance it might indicate something. Is that pimple a pimple? Hey, I don’t remember my neck feeling this lumpy. Boy, I sure do seem to have sinus issues a lot. Are these joint aches normal? Etc, etc, etc. As a kid, I felt absolutely invulnerable to worrying about my health. The first time I experienced true health anxiety is when my doctor pointed out a mole on my back and said “do you want to check this mole for cancer?” to which I replied, “oh, I guess so?”… only he didn’t. Because he checked with insurance, and insurance came back negative on it. I am still in my 20s. I’m not in the best health, but my everyday life is pretty uninhibited by health issues. I don’t wake up with coldsweats. So yeah, it could happen to me, but frankly it’s worth being skeptical at my age. But when the doctor pointed out that mole, they shattered the mental barrier I had between myself and cancer patients. I knew mentally that of course it could happen to me, but I had absolutely no idea that the signs of it could literally be hiding on my back, and I would be none the wiser. I googled and I learned a whole lot, and my intuitions were very wrong. In fact, I had many symptoms that can indicate various cancers. I heard stories about pimples that were not pimples, back pain that was not back pain, etc. people living normal lives who just went in for a checkup and suddenly faced certain death. I’ve mostly snapped out of the hypochondria mindset, but still today I wonder about some symptoms in a way I never would’ve before. My life is altered by this one thing a doctor said off hand. And for what it’s worth, I’m not saying he should not have done that. Insurance should’ve covered the biopsy just in case. I’ve outright noticed that sometimes, doctors will slightly edit your responses to things to get insurance to OK a diagnostic, and I think it’s in some part because they know that if you don’t get that peace of mind it could be damaging. Being hyper aware of your heart beat or super concerned about sleep apnea is not as bad as suffering from actual disease, but it’s certainly it’s own kind of hell. It’s weird to me because much like cancer patients, I viewed myself as separate from hypochondriacs and immune to it as a whole. A lesson learned the hard way, and now I feel a twinge every time I see a new headline about cancer or hypochondria.

cryoz 4y ago

Why do the CT scan in the first place if you are not going to do a biopsy if you find something?

psyc 4y ago

Not for the reasons central to the article, but my favorite is the No HPV Test For Men stance. Because men usually don't have symptoms and have far less risk of cancer than women..... Just take 10 seconds to ponder how myopic that is. But that's how the medical establishment thinks about health care.

OrvalWintermute 4y ago

This article is rather funny because it misses out on key facts of how doctors practice medicine these days. I listen to my supremely well educated plastic surgeon wife regularly discussing and giving guidance to office staff around patients in their private practice. Their general approach is to get patient statistics, and that is all, without the aggregated vital signs. I asked her once, "Why don't you get the patient vital signs too?" Her response was unexpected, "If we get patient vital signs, we immediately become liable for patient overall health. Our malpractice insurance is specific to the practice of medicine for plastic surgeons, and plastic surgeons only. Our front office staff are normally front office only, or aspiring doctors on a break between their undergrad and entry to medschool. Our practice uses no Nurse Practicioners, Physician's Assistants, or nurses. We're not set up, or staffed appropriately to deliver general medical care." Conclusion 1: Medical care is characterized by liability control; there are logistics/staffing aspects to medicine around specific types of care. Medical Diagnosis we think of as scans, remote tests. You get a CAT scan, you get an MRI, or X-ray, bam, 15 seconds, 5 minutes, or an hour later (after waiting in a hospital for hours) you're done and some radiologist or other specialist is interpreting the results and you have a diagnosis. That is true in some cases, but not others. If you get a positive mammogram, or a suspicious lump what is the next step? Welp, that is regularly one of two things - a needle biopsy, or an investigational biopsy. Needle implies small, thin, fairly painless. Not this needle - instead imagine a needle designed for tissue harvesting, like a horse sized needle. This big giant thing needs to go into your breast to suck up enough of the suspicious lump for a pathologist to examine it. Alternatively, you could have an investigational biopsy where a surgeon takes a small amount of tissue from inside your breast with a scalpel. Investigational biopsies via scalpel can be a big scam too, where a car accident occurs, a cut tendon in the hand, and the surgeon decides to open up the arm past the wrist to visualize all the soft tissue up the arm. Lucrative billing enhancements.. But, when it comes to breasts, we know that certain life changes predispose towards a positive mammogram for a limited time window. Stopping breast feeding being the foremost change that can cause suspicious lumps. Conclusion 2: Diagnostic tests can be quite painful, and, at the wrong time, quite unneeded. Some of them are damaging. Good medicine is about as much when to intervene, and when to test, just as much as it is about when not to intervene and when not to test.

4y ago

teekert 4y ago

This is so true. And I think we need more Bayesian models in Hospital IT systems to help with this. The probability needs to be updated, you shift to a new population with new evidence. It seems so clear, yet somehow it is so intuitive. Why? In many respects, Bayesian reasoning is just what we do, but then sometimes it fails us. We are just not good at accepting risks of any kind I think. Better to not put ourselves into this position seems to be the reasoning. Avoid that "The test told you so!" feeling...

norswap 4y ago

> If you do a CT scan and it shows a mass, you’ll order a biopsy. > But because that patient was low-risk, the harms of that biopsy will outweigh the benefits. > Thus, you shouldn’t do the CT scan. > What? If the harms of the biopsy outweigh the benefits, don’t do the damn biopsy! I'm not sure what the point of doing the CT scan if we're not going to act on its result. Sure, you gain the confidence that everything's gucci if it turns negative. Is that really worth the stress of the test going positive and the not doing the biopsy? Seems dubious to me.

gpt5 4y ago
The author is not arguing against efficiency in the medical system, but against the reasoning of - “if we test for X bad things will happen”
j-pb 4y ago
In a "perfect world" we'd all get routine checks, this would have two advantages: * Most illneses are easier to treat and have better long term outcomes in terms of morbidity, when they are detected early / in a asymptomatic stage. * We could collectively use the data collected from scanning "healthy" people, and adjust our bayesian priors so that we can more accurately adjust our diagnostic measures. E.g. common virus infections can give you brain lesions visible in MRI scans. However since MRIs are expensive we rarely scan healthy people so every lesion in an MRI is an immediate supicion of MS or other neurodegnerative diseases. We simply don't have good baselines for this. The latter would allow us to look at all the indicators more holistically to make a well balanced judgement if more invasive diagnostics are warranted.

the_sleaze9 4y ago

I think the author is correct in the acedemic sense, but ignorant of the reality of healthcare. If a doctor receives a test result that shows a suspicious mass, then neglects to order a biopsy to investigate further, there are 2 rough outcomes. 1. It was nothing 2. It was cancer If it turns out to be (2), the doctor and the practice/hospital/whatever gets sued for malpractice. On a more ranty note, why does everyone think they are better at other people's jobs than those people are? Where is the basic trust in the other? You think a doctor in the United States after ~15 years of school doesn't know that most biopsies turn out to be more harmful that useful? Come on. Restore some basic trust in other's competence.

axg11 4y ago
This is the reality. In fact, the situation is getting even more complicated as direct-to-consumer screening becomes more popular (e.g. full body MRI scans). Companies that are selling the health screenings are only incentivized to sell as many screenings as possible. Scans inevitably result in benign incidental findings far more often than they identify real health problems. Then the patient is directed to a specialist who is uninvolved with the screening company. The specialist is incentivized to aggressively investigate the finding out of fear of malpractice and due to pressure from the patient. Nobody has ever thanked their doctor for inaction. The end result far too often is a series of expensive and painful procedures with a large dose of anxiety. Of course screenings also save lives, but nobody is responsible for ensuring the benefits outweigh the harms at the macro level. I don't think any actor in that chain is malicious, it's just an example of poorly aligned incentives. Screening companies, doctors and patients all believe they are making the most optimal choice.
peteradio 4y ago
Presumably the patient can decline the biopsy? What happens to liability in that case? Does the doctor then have to decline to work with that patient further? What happens to liability if the doctor doesn't fire the patient? I agree there needs to be trust somehow, yet it seems practitioners hands are tied from a level above to toe the line for liability reasons rather than patient outcome. Is a doctor able to take into account all extenuating circumstances of a patient or only those predefined on a checklist passed on by a murky review process? What happens to patients who do research and find alternative (maybe better) opinions, well are they in network? Can a network have differing opinions among its practitioners?

bell-cot 4y ago

Amusing Idea: Let people apply for "Always Full Diagnostics" status, and accept ~0.01% of the population. The "lucky" AFD's would get every test, scan, biopsy, follow-up, exploratory surgery, etc. that was remotely plausible. The anonymized results from all those (mostly unwise) things would be a gold mine of public health data. And I suspect there'd be more than enough obvious adverse outcomes to convince most of the other ~99.99% that "more is better" does not apply to medical diagnostics.

qgin 4y ago

We're in an uncanny valley in medicine right now where it is good enough to give the impression that we have more control over human health than we actually do. More and more, the general public has come to see medicine as the Genius Bar service department for the human body. Everything that can be fixed, should be fixed. Let's get this thing back to like-new condition as we can, right? But in reality, medicine is still much closer to the older model of simply seeking to reduce human suffering. You will die of something one day and most likely you will have 8 other things wrong with you when it happens. Curing all cancer in all humans would only at about 2 years of average increased lifespan because of all the other causes of death that are creeping up right behind it in the background. So there is a tension here of what medicine should conceptually be doing. If, in the effort to "fix everything" (which is impossible), you actually introduce more suffering (by treating a diagnostic finding that may never have resulted in symptomatic disease), then many would say that's a failure of medicine.

daveguy 4y ago

This entire argument of it being "madness" hinges on the fact that a rational actor will know they are part of a low risk demographic and while they might worry, they won't seek medical care when they are informed they are low risk and "it's probably nothing". This is not a reasonable assumption. I'm not sure if the author has ever had a biopsy, but most people will seek out care if they get some concerning result, like a nodule on the lungs that's "probably benign because of your priors." Maybe you could opt in to "I am fully rational and will only make decisions using bayesian statistics with accurate priors." Maybe you could hide test results or generate false results based on probabilities as not to steer someone into an unnecessary procedure. (Yes this it tongue in cheek) Those who really really want to do that next test because they want the information are free to do that. But it seems like the exact mentality that will make you more prone to a botched biopsy. If you keep following the trail of more information you will get to a test that may not be best for your health outcome. That may be the initial x-ray. It seems that if you have not-fully-rational human beings and an obligation to truthfully inform them of the results of medical tests, then maybe not doing the test to begin with has significantly better health outcomes. Can you not chain bayesian probabilities?

lobocinza 4y ago

That's why I avoid reading stock market news during bear periods.

dataangel 4y ago

I think this article misses that there is a statistical conditioning issue. If the research literature says that patients who get scans showing lumps in their lungs have X% chance of having lung cancer, there is an implicit conditioning there in the patient having complained to the doctor of some kind of symptom that prompted the scan. X% isn't the probability of having cancer given lump on scan, it's the probability of having cancer given a lump on a scan in patients have breathing trouble. If you test too much you run the risk of there not being data about what the baseline is! Studies for a lung cancer treatment usually take 1000 random people and give them all lung x-rays and then wait to see how many get cancer later and survive the experimental treatment, instead they usually find 1000 people already diagnosed with lung cancer that had it diagnosed by traditional means (e.g. scans prompted by breathing problems). The same reasoning applies to deciding whether to do a biopsy -- most biopsies are going to be prompted by scans from a relevant patient complaint, so statistics computed to determine the risk/benefit tradeoff are implicitly conditioned on that. You need a separate study to determine the risk/benefit for incidental discovery.

chrismeller 4y ago

I’ve been shocked at the night and day attitude between the US and Estonia. The US definitely over-tests and Estonia just waits to see if you die and they don’t have to worry about it.