To be fair to (most) doctors, especially your primary physician, have to diagonose a huge range of conditions. The edge cases are rare and so they are not as well versed on them.
System specialists are an order of magnitude better. I.e. going to an Ear, Nose & Throat doctor if you have Asthma.
Disease specialists are the pinacle. Sometimes these are researchers rather than normal doctors.
It is actually counter-productive for doctors to learn too much about rare diseases.
When a patient presents with a set of symptoms, the doctor has to decide whether the patient has a boring common disease or the cool disease which is 100 times rarer. Human beings can't make good judgements about probabilities like that. If every doctor were trained to recognize a rare auto-immune disease that looks just like the flu, plenty of flu sufferers would be misdiagnosed. Far better to teach doctors the treat for flu and refer the cases that don't respond to a specialist.
It is a common problem with doctors fresh out of med school. Common enough that most doctors are taught to "not look for zebras when horses are more likely." If you spend enough time in a hospital you will hear veteran doctors dismiss interns and residents saying, "she's just looking for zebras."
It is far more common for a doctor to underdiagnose a patient that presents with flu systems but actually has the "cool, rare disease". I just read a good article on this, I'll try and look it up.
Anyway, I found what I was looking for; I had read an excerpt of a book called How Doctors Think, where the author discusses the availability heuristic:
In the theory, "availability" is defined as the tendency to judge the likelihood of explanation for an event by the ease with which relevant examples come to mind. In a clinical situation a diagnosis may be made because the physician often sees similar cases in his practice — for example, the misclassification of aspirin toxicity as a viral pneumonia, or the improper recognition of an essential tremor as delirium tremens due to alcohol withdrawal in an indigent urban setting. Groopman argues that a clinician will misattribute a general symptom as specific to a certain disease based on the frequency he encounters that disease in his practice.
Doctors are never going to be perfect; if you ask me following such a heuristic is probably going to work pretty well almost all of the time. As long as the doctor isn't a dick about it (with a god complex) and is willing to accept that they may be wrong..
In reference to my first comment: Mis-diagnosing "cool, rare diseases" as the flu by definition can only happen very rarely. Coupled with the fact that people are often mis-diagnosed with rare stuff, means that your original statement that "it is far more common..." is obviously untrue.
It must be frustrating if you are the person with the rare disease. But "not looking for zebras" serves the other 99.9% of people quite well..
You must be parsing my sentence differently than I am. Clarified:
It is far more common for a doctor to underdiagnose a patient that presents with flu systems but actually has the "cool, rare disease" [with the flu than it is to correctly diagnose them the first time].
In other words, within the ecosystem of "cool, rare diseases", it's far more likely to be mis- or under-diagnosed the first time than it is to be correctly diagnosed the first time. One reason for that is they're not common diseases (so the docs won't have a lot of experience diagnosing it), but another fascinating reason is that they have already sort of diagnosed you in their heads before getting into the data.
If you're interested in the topic, you should pick up the book I linked above. There's a fascinating study in there that tests this problem: the study takes two sets of identical x-rays with an obvious primary diagnosis like a cancerous tumor and in one set, they add another problem (blocked artery or torn heart valve or something else obviously serious and life-threatening). They give the x-rays to doctors, inform them of the primary diagnosis, have them look at the x-rays, and track their eye movements. Here's the crazy part: every one of the doctors lingered over that second, undisclosed problem, indicating they saw something wrong. Yet none of them reported the problem. (It's been a while so I might have gotten the specifics wrong, but the gist is there. It's really fascinating and I encourage you to read it on your own.)
On a personal note: take it easy with the "by definition" and "obviously untrue" stuff. I know this is the internet and all but it makes you seem hotheaded, especially when we might be misunderstanding each other.
You're right; I'm sorry, I should have given you the benefit of the doubt and parsed the sentence that way.
It is interesting about the 'bias' of doctors towards their own experience. I guess my point is that statistically this kind of 'bias' towards the most common syndromes is a net positive for society; it's an allocation of resources thing--we don't have so many doctors that we can afford them all to be running off on weird tangents investigating possible rare diseases that aren't there...
Again, sucks if you do happen to be the one in X thousand that has the rare disease. Am I being too utilitarian?
Regarding tone: apologies; I agree it was an overly flippant comment. It was more a reaction to some of the other doctor bashing that was going on in this thread that fails to see the woods for the trees. I see now that that wasn't your intention...
I have a genetic disease that shows up in 4/100k people, so rare, but not that rare. Any sizable town has at least a few dozen people with my disease.
In my experience, "an order of magnitude better" in specialists means they've at least heard of it, but know nothing about it. Every time I move, I have to spend some time educating my new specialist on the disease. I know damn well that every time one of them excuses themselves in the middle of the exam, they're going to look it up on the internet. It's pretty disheartening.
> I have a genetic disease that shows up in 4/100k people, so rare, but not that rare. Any sizable town has at least a few dozen people with my disease.
If one in 25k people has the disease, you need a 1 million+ population for city to have a 40 (a lowball "few dozen") incidences of the disease, assuming random distribution. There's only 10 cities in the United States that fit that description* and only London is big enough in the UK. There will be only 100 or so the medium sized states of say Utah or Nevada
Takes a lot more than a medium sized town and that sounds extremely rare condition to me.
I come from a medium sized town. Given your numbers, there's a good chance there is no one in the town has this disease and i wouldn't expect any of the doctors to be knowledgeable about it.
4/100k is still exceedingly rare. There are probably 100s or more diseases that show up in 5/100k so it's hard to know them all. Meanwhile the doctor probably sees the top 15 diseases all the time..
My girlfriend has a condition that affects 12% of the female population to a varying degree. Some doctors knew absolutely nothing about it. Some were able to solve it easily.
If the symptoms are 30% similar to a disease that 99.999% more common, and 70% similar to a disease that's 0.001% common, the doctor would still be correct most of the time by suggesting that the patient had the common disease, even though the symptoms were a better match to the rare disease.
Yep, it's also disheartening to see them holding a printout of one of the few articles available online, which I already know is pretty out-of-date and down-right wrong in places.
Why don't you just tell them that you're pretty well-versed? Doctors are pretty smart. I wouldn't presume to say this is always appropriate, but depending on the rapport they might listen attentively to what you know from your own research (though they would probably check before acting on it.)
Doctors know very well that a person with a specific rare disease has a lot more incentive to have spent in-depth research on it than they did when they last ran across it...
I mean, these days there are whole forums dedicatd to a specific disease. If you told the doctor, "You know, I ran across a forum for people like me, a lot of people have said they had very bad results with (x) despite the clinical trials, so I would prefer (y)"...you don't think they would listen to you?
You're making a lot of assumptions that aren't true. I regularly instruct doctors on my condition in detail, they do usually listen and are reasonable. However, I am often disappointed by the lack of depth of the research they do in advance of meeting (and billing me exorbitantly).
Recently, my sister (same condition) drove a couple hours to see a specialist who had obviously not read her file or done any research and made some truly awful suggestions (one that could certainly have lead to her death if she had followed it). He billed her for the time.
Doctors are like coders, some are orders of magnitude better than others. Some are so bad, they have a net negative impact on your health.
You speak like someone who probably hasn't spent a good chunk of their life as a patient. You are correct; the best doctors know the limit of their own knowledge and will respect a knowledgeable patient. I respect my top notch specialists more than anyone on the planet. But those are the best doctors. There are many more average and outright bad doctors, just like any other skilled profession. Some that can't keep their ego in check, some that just aren't very good at deconstructing a complex problem.
System specialists are an order of magnitude better. I.e. going to an Ear, Nose & Throat doctor if you have Asthma.
Disease specialists are the pinacle. Sometimes these are researchers rather than normal doctors.