Posts in: medicine

February lectures of note

The wellness visit

I am not a fan of “wellness” visits, those yearly exams that your insurance insists you should do even if you don’t have any medical problems. Evidence from randomized controlled trials suggests they don’t make any difference to people’s health, but they (obviously) contribute to the primary care physicians' workload.

Having said that, I recently reached a nice round number of years, so it was time to get my cholesterol checked and finally get a flu shot. I enjoyed the banter, but I could also see how and why there may be no health benefit. If annual exams are good for anything, it is to find chronic asymptomatic conditions that have long-term consequences — high blood pressure, high cholesterol and high glucose are the big ones at my age. Testing for them has the highest yield in a generally low-yield visit, so whoever is seeing you should get at least those three right.

After this morning I suspect most places are not doing it right. The person checking my blood pressure did not care at all about the correct technique: whether I still had my sleeves on when they placed the cuff, whether my feet were on the ground or hanging over the raised exam table, whether my legs were crossed, or whether I was talking while measurement was being taken. Worse yet, no one asked or cared whether I had anything to eat or drink before getting my blood drawn for the labs. I could have downed a sugar-and-cream-laden coffee with a Boston cream chaser minutes before the visit and no one would have known. This is the complete opposite of Serbia, where they drill into you at an early age that you must have nothing to eat or drink — water excepted — before getting your blood drawn for anything; which is an extreme of its own kind but one that at least doesn’t result in lab results that you can’t interpret.

At best the loose approach to testing leads to more labs having to be drawn if and when something comes back out of range and the doctor wonders why. At worst it leads to misdiagnosis (“Your cholesterol is through the roof, you’d better be on a statin!") or missed diagnosis (“Your cholesterol is a bit too high but you ate before the labs were drawn so it’s probably just from the food.") — neither is good.

Even when properly done, I don’t think the annual exams are worth it. There are plenty of reasons to see the physician for other things, and sneaking in a blood pressure check and some labs on top of those is easy enough without overburdening the system. For those fortunate enough to be without ailments, a visit every 5–10 years to make sure all the screenings are up to date sounds about right. The paradigm of treating your body as a car to be taken to the shop for scheduled maintenance is wrong: our bodies aren’t intelligently designed mechanisms with replaceable parts that wear out at a predictable rate, and we can’t be taken apart and put back together at a whim. The trend of renaming the annual exam to something else recognizes this reality.

The replacement term, wellness visit, is not much better. In theory it should make the doctor (or nurse practitioner) enhance the lives of people they are seeing by taking a more holistic approach: “You are not a patient, you are a person.” In practice, it turns doctors into box-checkers: are you suicidal (yes/no), do you drink alcohol (yes/no), do you use illicit drugs (yes/no). It takes time away from things doctors were trained for — to treat disease that can be treated, provide council about the diseases that can’t, and know the difference between the two — and makes them do things that are as important, maybe more so, but not in their area of expertise.

The problem isn’t unique to medicine. It’s good to have the police around to deal with murder and theft, not so much when there is a domestic dispute or an acute psychotic episode, now (holistically?) called “a mental health crisis”. They used to be matters for the extended family or neighbors to deal with, not an outside force. Wherever the two were lost, public and private services picked up some of the responsibilities; the doctors seem to have gotten the role of the friendly ear, listening to the issues that used to be mulled over a cup of tea, or — sure, I’ll go there — in the bowling alley. This is a job they were not trained to do and for which they receive no compensation, so in that sense it is fair: the (American) society got what it paid for.

Theory and practice, drug cost edition

You know the one about theory and practice? That in theory there is no difference between the two, but in practice there is. Yesterday’s post from the economist Alex Tabarrok about better drugs costing more is a great example. Per Tabarrok:

Consider two lightbulbs, one lasts for 2 years the other lasts for 1 year. Which lightbulb is more profitable to sell? Any sensible analysis must begin with the following simple point: A lightbulb that lasts for 2 years is worth about twice as much as a lightbulb that lasts one year. Thus, assuming for the moment that costs of production are negligible, there is no secret profit to be had from selling two 1-year lightbulbs compared to selling one 2-year lightbulb. The firm that sells 1-year lightbulbs hasn’t hit on a secret profit-sauce because its customers must come back for more. If it did it could sell really profitable 1-month bulbs!

The same thing is true for pharmaceuticals. A treatment that lasts for 10 years is worth about ten times as much as an annual treatment. Or, to put it the other way, a treatment that lasts for 10 years is worth about the same as 10 annual treatments producing the same result. (n.b. yes, discounting, but discounting by both consumers and firms means that nothing fundamental changes.)

Too bad that drugs aren’t lightbulbs, hospitals aren’t hardware stores, and that treating people isn’t the same as selling tchotchkes. Well, maybe they are the same in theory, but we looked at actual cancer drugs, and their actual cost, and how much the cost per year correlates with actual improvements in survival, and the answer was: not at all. Novelty of the mechanism of action doesn’t have much to do with the cost either. We didn’t go into what affected the cost, but as I’ve written before, President Biden made a good guess.

So yes, lightbulbs. Cute story, professor Tabarrok, but true only in theory.

Here are Mr. and Mrs. Phillip Wase, as seen at the Smithsonian American Art Museum.

Painting of an elderly man and woman sitting in their parlour.

The odd and disengaged looks they both have aside, does Mrs. Wase look like she has a medical condition? Here is a hint.

Close-up of Mrs. Wase's hands holding a book. Fingers look swollen and misshapen in places.

This looks like textbook swan neck deformity, so Mrs. Wase probably had rheumatoid arthritis.

Tim Harford on the UK’s crumbling health care system:

In the case of St Mary’s Hospital in London, these weak foundations are all too literal. The Financial Times recently reported that the hospital had rotting floor joists, frequent flooding, a hole in one lavatory floor that led to a car park, a ward closed due to a collapsed ceiling, and sewage backing up out of the drains and into the outpatient department. Yet St Mary’s is no longer regarded as an urgent priority for investment, because five other hospitals appear to be in more imminent danger of falling down.

15-some years ago, when I was contemplating what to do after graduating from medical school, the UK was on the list of places for potential residency. It quickly got crossed off because it was hostile to foreign doctors — especially compared to the US — but good for me that it was!

December lectures of note

Not too much this month, for understandable reasons:

It gives me no pleasure to delete a feed that I have been following off and on for more than a decade now, but the logorrhea combined with intentional scandal-seeking behavior has become too much. Screen after awful screen of gotchas and callouts in a single post. Whatever for?

Quote of the morning:

My view is that any theory of what is wrong with American health care is true because American health care is wrong in every possible way.

Very true! This is from Alex Tabarrok’s review of what seems to be quite a misguided book about America’s handling of covid. I’ll take Tyler’s side of that debate.

There is both a science and an art to medicine. The “art” part usually comes into play when we talk about bedside manner and the doctor-patient relationship, but recognizing and naming diseases — diagnosis — is also up there. José Luis Ricón wrote recently about a fairly discrete entity, Alzheimer’s disease, and how several different paths may lead to a similar phenotype. This is true for most diseases.

But take something like “cytokine release syndrome”, or “HLH”, or any other syndromic disease that is more of a suitcase phrase than anything, and that can present as a spectrum of symptoms. Different paths to different phenotypes, with only a sleigh of molecular storytelling to tie them together. Yet somehow it (mostly) works. It’s quite an art.

Why not use machine learning to rank residency applicants?

I just finished attending a 1-hour career panel for UMBC undergrads thinking about medical school, and the one thing anyone interested in practicing medicine in America should know is that you really, really, really need to know how to answer multiple choice questions. It doesn’t matter how smart, knowledgable, or hard-working you are: if you don’t have the skills needed to pick the one correct answer out of the four to six usually given, be ready to take a hit on how, where, and whether at all you can practice medicine in the US.

To be clear, this is a condemnation of the current system! Yes, there are always tradeoffs: oral exams so prevalent in my own medical school in Serbia weight against the socially awkward and those who second-guessed themselves. But the MCQs are so pervasive in every aspect of evaluating doctors-to-be (and practicing physicians!) that you have to wonder about all the ways seen and unseen in which Goodhart’s law is affecting healthcare.

What would the ideal evaluation of medical students look like? It wouldn’t rely on a single method, for one. Or, to be more precise, it wouldn’t make a single method the only one that mattered. Whether it’s the MCAT to get into medical school, USMLE to get into residency and fellowship, or board exams to get and maintain certification, it is always the same method for the majority of (sub)specialties. Different organizations, at different levels of medical education, zeroing in on the same method could indeed mean that the method is really good — see: carcinisation — To save you a click: it is “a form of convergent evolution in which non-crab crustaceans evolve a crab-like body plan”, as per Wikipedia. In other words, the crab-like body plan is so good that it evolved at least five different times. but then if it is so great to be shaped like a crab, where are our crab-like overlords?

Being a crab is a great solution for a beach-dwelling predatory crustacean with no great ambitions, and MCQs are a great solution to quickly triage the abysmal from everyone else when you are pressed for resources and time. But, both could also be signs of giving up on life, like how moving to your parents' basement is the convergence point for many different kinds of failed ambition.

Behind the overuse of MCQs is the urge to rank. Which, mind you, is not why tests like USMLE were created. They were, much like the IQ tests, meant to triage the low-performing students from the others. But the tests spits out a number, and since a higher number is by definition, well, higher than the lower ones, the ranking began, and with it the Goodhartization of medical education. The ranking became especially useful as every step of the process became more competitive and the programs started getting drowned in thousands of applications, all with different kinds of transcripts, personal statements, and letters of recommendation. The golden thread tying them all together, the one component to rule them all, was the number they all shared — the USMLE score.

But then the programs started competing for the same limited pool of good test-takers, neglecting the particulars of why a lower-scoring candidate may actually be a better match for their program. Bad experience all around, unlike you are good at taking tests, in which case good for you, but also look up bear favor. On the other hand, there is all this other information — words, not numbers — that gets misused or ignored. If only there was a way for medical schools and residency programs to analyze the applications of students/residents that they found successful by whatever metric and make a tailor-made prediction engine.

Which is kind of like what machine learning is, and it was such a logical thing to do that of course people tried it, several times, with mixed success. It was encouraging to see that two of these three papers were published in Academic Medicine, which is AAMCs own journal. One can only hope that this will lead to a multitude of different methods of analysis, a thousand flowers blooming, etc. The alternative — one algorithm to rule them all — could be as bad as USMLE.

The caveat is that Americans are litigious. Algorithmic hiring has already raised some alarm, so I can readily imagine the first lawsuit from an unmatched but well-moneyed candidate complaining about no human laying their eyes on the application. But if that’s the worst thing that could happen, it’s well-worth trying.