Echoes of Semmelweis

As hard as it is to believe, I’ve been a physician for 23 years now and a fully trained surgeon for over 15 years. If there’s one thing I’ve learned in that time, it’s most doctors really, really don’t like to be told what to do. I don’t know if part of it comes from all the long years of medical school and residency, with fellowship tacked on for many, during which we’re relentlessly told what to do by more senior residents, fellows, and attendings or if it has something to do with the personality traits that lead young people to go into medicine, particularly surgery. It’s probably a little of both.

Be that as it may, one negative consequence of this particular personality trait is that many physicians are surprisingly–shockingly, even–resistant to the very concept of evidence-based medicine. For purposes of this post, regular readers should be aware that, just this once, I’m not going to worry too much about the distinction between evidence-based medicine (EBM) and science-based medicine (SBM), mainly because in the case of plausible treatments based on sound science the differences between EBM and SBM tend to disappear because the results of clinical trials usually represent the culmination of preclinical investigations that establish the science behind the treatment being tested. Just the other day I saw a post by a blogging orthopedic surgeon who goes by the ‘nym The Angry Orthopod (AO) entitled Evidence-based medicine removes a physician’s autonomy. It’s an annoying little screed chock full of straw men attacks against EBM/SBM slathered with copious quantities of arrogance and disdain for scientists and an inflated sense of the author’s own ability to synthesize the medical literature into his approach to patient care. You’ll see what I mean in a second.

After sarcastic rejoinders about EBM, the AO starts in earnest:

Evidence based medicine, or EBM, may be just another way to remove a physician’s autonomy. This trend has marched on for years, castrating us bit by bit. EBM is nothing more than the old process of peer-reviewed journal articles, but now there’s a classification systems that grades according to the article’s strengths or weaknesses. In other words, it’s to help the non-academic dummies tell the difference between crap and quality. In the U.S., a five-level scale is favored, while the U.K. prefers a four-stage system, and there are others.

AO says that as though it were a bad thing.

A little Orac-ian sarcasm aside, though, this is a common viewpoint, namely that somehow physicians should have near absolute autonomy to do whatever the heck they want treating patients (constrained, apparently, only by malpractice laws and the weak enforcers that are state medical boards), that they are somehow all-powerful, all-knowing gods of medicine whose judgment must not be questioned. Indeed, what I sense more than anything else from AO is resentment and suspicion at anything that might constrain his autonomy. To a certain extent this is not a bad thing (after all, part of being a profession is to have a degree of autonomy to set standards of performance), but this is ridiculous. What is apparently pissing AO off so much is an attempt to systematize how evidence is evaluated and applied when it comes to clinical questions, in essence using that system to provide both information and guidelines to physicians about what the latest evidence shows. AO’s apparent confidence in his own abilities notwithstanding, a lot of doctors could actually use the help. Many, myself included, even welcome the assistance. But not AO;

My interest in this is truly for the end recipient: you, the patient. I think EBM at its core is a good thing, but its ultimate use must be questioned. The obvious objective for EBM is to arrive at the best care for the patient with a certain diagnosis. The subversive goal of EBM is to “mechanize” the whole medical delivery system and put the decision-making process on a prescribed pick list.

I’ve heard this sort of complaint many, many times before. In particular, I’ve heard it with respect to checklists, even though there is quite a bit of evidence that judiciously used checklists improve patient care and patient outcomes. There’s a paranoid component to these sorts of objections to EBM/SBM as well. Often physicians ascribe to the motives of supporters of EBM as a desire for “control” or claim that it’s insurance companies trying to save money. In fact, AO makes exactly that argument near the end of his post. It’s very predictable; any time you see broadsides against EBM like this inevitably the person writing the screed will imply that insurance companies and government payers like Medicare are behind it all. They’re not, but not surprisingly third party payers do like and encourage EBM because it does have the potential to improve outcomes and (possibly) save money. What’s often forgotten, though, by doctors like the AO is that EBM can also cost money. What if the literature finds that a a very expensive intervention is the most effective? Or that, for example, screening for cancer with breast MRI is far more effective than mammography? When it comes to cost, EBM can cut both ways; yet its critics (and sometimes its proponents) always seem to assume that it will only ever cut costs.

Financial considerations aside, though, as I’ve said before, it all appears to boil down to not wanting to be told what to do.

In fact, “cookbook medicine,” as AO so disparagingly calls EBM and evidence-based guidelines is very important in improving patient outcomes; yet all too often physicians don’t follow them. One of the commenters took AO to task by pointing out so aptly that, even after many unassailable studies have shown the benefits of aspirin, beta blockers, ACE inhibitors, and other interventions that there are still quite a few patients whose outcomes are jeopardized because these modalities are not appropriately prescribed by their doctors. My favorite example is the fact that it’s been shown time and time again that antibiotics do not do any good for viral infections. Yet large numbers of physicians continue to prescribe them for obvious viral illnesses. As commenters pointed out, there is no “subversive” goal behind EBM. The goal of EBM is quite overt, and that’s to standardize the parts of medicine that can be standardized based on evidence, leaving the more complex problems and questions that are either not well addressed by clinical trials or for which evidence is conflicting for physicians to exercise their professional judgment upon. Think of it as triage, in which guidelines for clinical situations on which the literature is clear are established and a framework for evaluating the literature for clinical situations that aren’t so clear is created in order to assist physicians make decisions.

It’s rather interesting to look at one of the article that AO references as a criticism of EBM. Among other complaints, the authors of the article criticize EBM based on philosophy:

The first type of criticism involves the philoso- phical underpinnings of EBM, which is based on empiricism. In its rawest form, EBM elevates experimental evidence to primary importance over pathophysiological and other forms of knowledge, and implicitly assumes that scientific observations can be made independent of the theories and biases of the observer.

What I found hilarious about this critique is that it’s exactly the opposite of the criticism of EBM that many of us make, namely that it undervalues basic science and knowledge of pathophysiology that is well-established and overvalues forms of clinical trials that, in the case of highly implausible therapies like homeopathy, easily produce false positives. The rest of their complaint boils down to a load of postmodernist nonsense and complaints that science is “biased.” The authors also complain that EBM doesn’t incorporate “professional experience” into it. Of course, professional experience shouldn’t be part of EBM. That’s rather the point, to minimize reliance on subjective standards like “professional experience,” which is why it is entirely appropriate to relegate expert opinion to the lower rungs of the evidence hierarchy. Professional experience is what a physician uses to evaluate EBM guidelines, not a part of those guidelines.

Not that this stops AO from going further into hostility against EBM:

Of course the randomized, triple-blinded, placebo-controlled study is the research crown jewel, but those studies are far and few between, especially in our paranoid, liability-fearing world. Who decides the assignment of a level? Does a higher-level study render all lower ones irrelevant by default? Can’t I decide which articles are accurate and relevant, to me?

Apparently AO can’t. After all, he can’t figure out whether a higher level study renders all the lower level ones irrelevant by default. I know, I know, he’s asking rhetorical questions, but, really, his hostility towards EBM makes me wonder whether he’s equally hostile towards evidence that doesn’t fit his preconceptions about how orthopedics should be practiced. It’s often been said that there are two kinds of medicine, EBM/SBM and “experience-based” or “dogma-based” medicine. AO’s protestations to the contrary notwithstanding, his utter confidence in his own ability to evaluate the literature without assistance (and that’s all EBM really is when it comes down to it, assistance in synthesizing the medical literature) leads me to think that AO falls closer to the dogma-based, rather than evidence-based, medicine camp.

As I said before, I’ll say again: AO’s objection to EBM seems to be far more rooted in not wanting to be told what to do, even going so far as to compare doctors as “lambs to the slaughter”:

Doctors, the ultimate holders of the key to patient care, are being lead to slaughter in years to come, and EBM is part of the puzzle.

And to conclude:

If allowed, EBM will change medicine from a practice of individual-based, case-by-case care to cookie-cutter cookbook recipes. Maybe some docs need a cookbook but I don’t. The docs I respect don’t either.

Comparing EBM to “cookbook medicine” betrays a total lack of understanding of what EBM is. it’s not cookbook medicine, and I say that as someone who practices by evidence-based guidelines. Most of the physicians at our cancer center practice based on the National Comprehensive Cancer Network (NCCN) guidelines. These guidelines are extensive, comprehensive, and detailed, but even with a high level of detail there’s still a hell of a lot of clinical judgment that goes into our practice because we often encounter situations where it is not clear which guidelines apply or for which there is no real guideline. Moreover, the guidelines themselves often have caveats and appeals to clinical judgment or a list of evidence-based choices. One example that we encounter a lot now is the question of whether in breast cancer a surgeon should remove the rest of the lymph nodes under the arm after one or two of them are found to be positive for metastatic cancer. In the past, we used to do it routinely, but then there was a major study earlier this year that says it’s not necessary in most cases. What to do? It’s not likely that there will be another study to answer the question because the study (ACOSOG Z0011) never managed to complete accrual because of increasing resistance among patients to being randomized to axillary dissection (removing all the lymph nodes under the arm). Consequently, we have to use our clinical judgment about how much credence we place in this one study in the context of all the studies that went before because Z0011, for all its flaws, is currently the best study we have about this question, and for practical reasons probably the last.

It’s sometimes been said that those who complain the most about EBM and show the most hostility towards the very concept are the ones in most dire need of EBM. I would tend to agree, because hostility towards the concept to EBM in particular to me implies hostility towards scientific evidence in general when it doesn’t fit with one’s current practice and an overweening arrogance that lends far more faith to one’s own “clinical judgment” than is warranted. Humility is in order, and unfortunately it’s in short supply among many physicians like AO.

It’s tempting to conclude by recalling a very famous physician from 150 years ago by the name if Ignaz Semmelweis, so tempting that I am going to do it. Pretty much every doctor knows who Semmelweis was. Basically, he was an Austrian physician who noticed a much higher death rate from puerperal fever in the obstetrical wards administered by physicians and medical students than in the wards administered by midwives and midwife students. To make a long story short, Semmelweis noticed a link between cadavers and a puerperal fever-like disease and hypothesized that the source of the higher rate of puerperal fever in the physician-administered obstetrical ward was material from the cadavers that physicians and medical students brought with them after doing autopsies and not washing their hands. (Disgusting, I know.) To test his hypothesis, Semmelweis mandated that anyone doing autopsies had to wash their hands with a solution of chlorinated lime (basically, bleach) before examining or working on patients. As a result the death rate from puerperal fever plummeted dramatically.

Unfortunately, the reason why the story of Semmelweis is a cautionary tale in medicine is that Semmelweis had difficulty convincing his fellow physicians of his results. Doctors had a hard time accepting the evidence, as blindingly clear cut as it was, and had a hard time accepting that they might be harming patients. In essence, many (but not all) of them refused to change their practice based on this evidence. In reading AO’s little broadside against EBM/SBM, I couldn’t help but hear echoes of Semmelweis’s critics from that long ago time. I like to think we as a profession had advanced beyond that, but every so often I’m reminded that our time is not as different from that of Semmelweis as I would like to think. I also can’t help but wonder if AO is a member of the AAPS, whose Ayn Randian belief that they are “supermen” (and women) whose egoism and genius will inevitably prevail over timid traditionalism and social conformism–not to mention pesky things like EBM that seek to constrain their creativity and genius with mundane things like evidence. Such thinking leads to some very unfortunate occurrences, such as the acceptance of cranks as “brave maverick doctors.” It is not a coincidence that the AAPS as an organization is very hostile towards the very concept of EBM and uses arguments very much like those of AO, arguments based mainly on how EBM is “castrating us, bit by bit.” The analogy reveals a lot about AO’s mindset and that of those who show similar hostility towards EBM.

But then what do I know? I’m just one of those pointy-headed academics who think that the systematization of evaluating scientific evidence in medicine is in general a good thing in the vast majority of cases.