Science-Based Medicine

If there’s one thing I’ve learned over the past seven years or so that I’ve been blogging, first at my other “super secret” (or, more accurately, super “not-so-secret”) blogging location, and then the four years I’ve been blogging here at Science-Based Medicine (SBM), it’s that the vast majority of “alternative medicine,” “complementary and alternative medicine” (CAM), and “integrative medicine” (IM) treatments (or whatever you want to call them) are nothing more than placebo medicine. True, there are exceptions, such as herbal treatments, mainly because they can contain chemicals in them that are active drugs, but any critical look at things like homeopathy (which is water), reiki (which is faith healing substituting Eastern mystical beliefs for Christianity), acupuncture (whose effects, when tested rigorously, are found to be nonspecific), or “energy healing” must conclude that any effects these modalities have are placebo effects or responses. Given writings on this topic by Steve Novella, Mark Crislip, Harriet Hall, Peter Lipson, myself, and others, this should be abundantly clear to readers of this blog, but, even so, it bears repeating. In fact, it probably can’t be repeated enough.

There was a time not so long ago when proponents of unscientific medicine tried very, very hard to argue that their nostrums have real effects on symptoms and disease above and beyond placebo effects. They would usually base such arguments on small, less rigorously designed clinical trials, mainly because, if there’s another thing I knew before from my medical education but that has been particularly reinforced in me since I started blogging, it’s that small clinical trials are very prone to false positives. Often they’d come up with some handwaving physiological or biological explanation, which, in the case of something like homeopathy, often violated the laws of chemistry and physics. Be that as it may, the larger and more rigorously designed the clinical trial, the less apparent effects become until, in the case of CAM therapies that do nothing (like homeopathy), they collapse into no effect detectable above that of placebo. Even so, there are often enough apparently “positive” clinical trials of water (homeopathy) that homeopaths can still cling to them as evidence that homeopathy works. Personally, I think that Kimball Atwood put it better when he cited a homeopath who said bluntly, “Either homeopathy works, or clinical trials don’t!” and concluded that, for highly implausible treatments like homeopathy, clinical trials as currently constituted under the paradigm of evidence-based, as opposed to science-based, medicine don’t work very well. Indeed, contrasting SBM with EBM has been a major theme of this blog over the last four years. In any case, for a long time, CAM enthusiasts argued that CAM really, really works, that it does better than placebo, just like real medicine.

Over the last few years, however, some CAM practitioners and quackademics have started to recognize that, no, when tested in rigorous clinical trials their nostrums really don’t have any detectable effects above and beyond that of placebo. A real scientist, when faced with such resoundingly negative results, would abandon such therapies as, by definition, a placebo therapy is a therapy that doesn’t do anything for the disease or condition being treated. CAM “scientists,” on the other hand, do not abandon therapies that have been demonstrated not to work. Instead, some of them have found a way to keep using such therapies. The way they justify that is to argue that placebo medicine is not just useful medicine but “powerful” medicine. Indeed, an article by Henry K. Beecher from 1955 referred to the “powerful placebo.” This construct allows them then to “rebrand” CAM unashamedly as “harnessing the power of placebo” as a way of defending its usefulness and relevance. In doing so, they like to ascribe magical powers to placebos, implying that placebos can do more than just decrease the perception of pain or other subjective symptoms but in fact can lead to objective improvements in a whole host of diseases and conditions. Some even go so far as to claim that there can be placebo effects without deception, citing a paper in which the investigators — you guessed it! — used deception to convince their patients that their placebos would relieve their symptoms. Increasingly, placebos are invoked as a means of “harnessing the power of the mind” over the body in order to relieve symptoms and cure disease in what at times seems like a magical mystery tour of the brain.

Part of what allows CAM practitioners to get away with this is that placebo effects are poorly understood even by most physicians and, not surprisingly, even more poorly understood by the public. Moreover, we all like to think that we have more control than we do over our bodies and, in particular, illnesses and symptoms, which is why the selling of placebo effects as a means of harnessing some innate hidden power we have to control our own bodies through the power of mind is so attractive to so many, including some scientists and physicians. Exhibit A is Ted Kaptchuk, the researcher from Harvard University responsible for spinning an interesting study of placebo effects in asthma into the invocation of the power of placebo. Kimball Atwood has written extensively about Kaptchuk recently, revealing his rather dubious background and arguments. More recently, however, Kaptchuk seems to be everywhere, appearing in articles and interviews, promoting just the argument I’m talking about, that CAM is a way of harnessing placebo effects, so much so that I felt it was time to take a look at this argument.

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One of the recurring topics here at SBM is the idea of the placebo: What it is, what it isn’t, and how it complicates our evaluation of the scientific evidence. One my earliest lessons after I started following this blog (I was a reader long before I was a writer) was that I didn’t understand placebos well enough to even describe them correctly. Importantly, there is no single “placebo effect”. They are “placebo effects”, a range of variables that can include natural variation in the condition being studied, psychological factors and subjective effects reported by patients, as well as observer bias by researchers studying a condition. All of these, when evaluated in clinical trials, produce non-specific background noise that needs to be removed from the analysis. Consequently, we compare between the active treatment and the placebo to determine if there are an incremental benefits, to which we apply statistical tests to determine the likelihood that the differences between the intervention and the placebo groups are real. Removed from the observational nature of the clinical trial, we can’t expect the observed “placebo effects” to persist, as they’re partially a consequence of the trial itself. A more detailed review of placebos is a post in and of itself, so I’ll refer you to resources that describe why placebo effects are plural, that placebo effects are subjective rather than objective and there is no persuasive evidence to suggest that placebo effects offer any health benefits. What’s most important is the understanding that placebo effects are a measurement artifact, not a therapeutic effect.

Placebo effects are regular topics within in SBM posts because an understanding of placebo effects is essential to evaluating the evidence supporting (so-called) complementary and alternative medicine, or CAM. As better quality research increasingly confirms that the effects from CAM are largely, if not completely, attributable to placebo effects, we’ve seen the promoters of CAM shifting tactics. No longer able to honestly claim that CAM has therapeutic effects, “treatments” such as acupuncture or homeopathy are increasingly promoted as strategies that”harness the power of placebo” without all the pesky costs or side effects of real medical interventions. But this is simply special pleading from purveyors and promoters. Unable to wish away the well-conducted trials that show them to be indistinguishable from placebos, they instead are spinning placebo effects as meaningful and worthy of pursuit – ideally with your favourite CAM therapy. Again, I’ll refer you to posts by David Gorski and Steven Novella who offer a more detailed description of how negative results can be spun to look positive. Because CAM’s effects are indistinguishable from placebo, we should not invest time and resources into pursuing them – we should instead focus on finding treatments that are demonstrably superior to placebo.

But what if physicians are already using placebos widely in practice? Setting aside the ethical issues for now, widespread placebo usage might suggest that physicians believe that placebos are effective treatments. And that’s the impression you may have had if you skimmed the medical headlines last week:

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Last week, I discussed a rather execrable study. Actually, the study itself wasn’t so execrable, at least not in its design, which was a fairly straightforward three-arm randomized clinical trial. Rather it was the interpretation of the study’s results that was execrable. In brief, the authors tested an “energy healing” modality known as “energy chelation” versus a placebo (sham “energy chelation”) and found, as is so often the case in studies of “complementary and alternative medicine” (CAM) or “integrative medicine” (IM) that both modalities did better than no treatment on the primary outcomes but that the “real” treatment (if one can call energy chelation “real treatment”) produced outcomes that were statistically indistinguishable from the “sham” treatment. Not surprisingly, the next move on the part of the researchers was to do a bunch of comparisons, and, as is so often the case (particularly when one fails to correct statistically for multiple comparisons), they found a couple of secondary endpoints with barely statistically significant differences and trumpeted them as meaning that their “energy chelation therapy” has “significant promise for reducing fatigue.” They then argued that the study was also ” designed to examine nonspecific and placebo elements that may drive responses.”

Which brings us to the “power” of placebo.

As I was contemplating what I wanted to discuss this week, I thought about the study that Drs. Coyne, Johansen, and I objected to, but then I also thought about Dr. Crislip’s post last week and post I did about a month ago in which I noticed how lately CAM apologists seem to be—shall we say?—retooling their message in the wake of negative trial after negative trial of their implausible treatments. Gone (mostly) are claims of powerful specific effects and efficacy from treatments such as various “energy healing” modalities, acupuncture, homeopathy, and the like themselves, to be replaced by claims that physicians should embrace CAM because it’s “harnessing the power of placebo” to produce “powerful mind-body healing.” It’s a powerful message that has sucked in people who normally would be considered skeptics, such as Michael Specter, who, as I described, apparently bought into the message sufficiently that when Ted Kaptchuk was making the media round right before the holidays he happily published a fairly credulous interview with him entitled, The Power of Nothing: Could Studying the Placebo Effect Change the Way We Think About Medicine? (My answer: Very likely no.) Even Ira Flatow of Science Friday fell hard for Kaptchuk’s message, declaring at the beginning of the interview that Kaptchuk’s irritable bowel syndrome study is evidence that “placebos work even when patients are in on the secret.” (It’s not.)

That skeptics and scientists find the idea that the mind has the power to heal the body, often referred to as “self-healing” or “mind-body healing,” so seductive should probably not be surprising. After all, who wouldn’t want to be able to cure themselves simply by willing it to be so? It’s a concept that, like so many concepts in CAM, goes far back into ancient times and stretches forward to today in ideas like The Secret, which goes quite a bit beyond the whole idea of “mind-body healing” or healing yourself because you wish it to be so, and declares that you can have virtually anything you want simply by thinking the right thoughts. In fact, to me it appears that the “powerful placebo” is being drafted in the service of supporting what are, at their core, mystical beliefs far more than science. I’d like to elaborate on that idea a bit more than I did last time I discussed this isssue, where I concluded by writing:

In the end, all too much of the rebranding of CAM as placebo and the selling of placebos as some sort of powerful “mind-body healing” strikes me as being much like The Secret, in which wishing makes it so.

Let’s take a look at just how far this goes.
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King Arthur: Now stand aside, worthy adversary.
Black Knight: ‘Tis but a scratch.
King Arthur: A scratch? Your arm’s off.
Black Knight: No it isn’t.
King Arthur: What’s that, then?
Black Knight: [after a pause] I’ve had worse.
King Arthur: You liar.
Black Knight: Come on ya pansy.King Arthur: [after Arthur's cut off both of the Black Knight's arms] Look, you stupid Bastard. You’ve got no arms left.
Black Knight: Yes I have.
King Arthur: Look!
Black Knight: It’s just a flesh wound.Monty Python and the Holy Grail

—————
I am, I think, in a minority on this blog, in that I do not think there is a placebo effect. Period. None. Zip. Zero. Nada. Zilch.

For analysis purposes, I divide the lack of placebo effect into outcomes that do not occur with objective measurement and those that do not occur with subjective measurement.

Why the dichotomy? Those studies where there have been an active treatment, a placebo treatment and an observation group, have demonstrated no difference between observation and placebo (1). To summarize from the conclusion of the compelling NEJM review:

“We found little evidence in general that placebos had powerful clinical effects. Although placebos had no significant effects on objective or binary outcomes, they had possible small benefits in studies with continuous subjective outcomes and for the treatment of pain. Outside the setting of clinical trials, there is no justification for the use of placebos.”

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About three weeks ago, ironically enough, right around the time of TAM 9, the New England Journal of Medicine (NEJM) inadvertently provided us in the form of a new study on asthma and placebo effects not only material for our discussion panel on placebo effects but material for multiple posts, including one by me, one by Kimball Atwood, and one by Peter Lipson, the latter two of whom tried to point out that the sorts of uses of these results could result in patients dying. Meanwhile, Mark Crislip, in his ever-inimitable fashion, discussed the study as well, using it to liken complementary and alternative medicine (CAM) as the “beer goggles of medicine,” a line I totally plan on stealing. The study itself, we all agreed, was actually pretty well done. What it showed is that in asthma a patient’s subjective assessment of how well he’s doing is a poor guide to how well his lungs are actually doing from an objective, functional standpoint. For the most part, the authors came to this conclusion as well, although their hedging and hawing over their results made almost palpable their disappointment that their chosen placebos utterly failed to produce anything resembling an objective response improving lung function as measured by changes (or lack thereof) in FEV1.

In actuality, where most of our criticism landed, and landed hard—deservedly, in my opinion—was on the accompanying editorial, written by Dr. Daniel Moerman, an emeritus professor of anthropology at the University of Michigan-Dearborn. There was a time when I thought that anthropologists might have a lot to tell us about how we practice medicine, and maybe they actually do. Unfortunately, my opinion in this matter has been considerably soured by much of what I’ve read when anthropologists try to dabble in medicine. Recently, I became aware that Moerman appeared on the Clinical Conversations podcast around the time his editorial was published, and, even though the podcast is less than 18 minutes long, Moerman’s appearance in the podcast provides a rich vein of material to mine regarding what, exactly, placebo effects are or are not, not to mention evidence that Dr. Moerman appears to like to make like Humpty-Dumpty in this passage:
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Science journalist Sharon Begley wrote a recent piece in The Saturday Evening Post about Placebo Power. The piece, while generally better than the typical popular writing on placebos, still falls into the standard placebo narrative that is ubiquitous in the mainstream media. The article is virtually identical to a dozen other articles I have read on placebo effects in the popular press, and most significantly fails to even question that narrative.

Begley is generally one of the better science journalists, although I have had my disagreements with her – specifically over her attitude toward the relationship between skeptics and the media. She seems to have a distorted and negative view of skeptics and does not think that the media can or should help us in our “debunking crusade.” (The term itself speaks of a fundamental misunderstanding of the modern skeptical movement.)

I have also parted ways with Begley over her view of the relationship between science and medicine. She seems to have a fairly negative view of doctors, fueled in part by her imperfect grasp of medical science. This is the risk with even the best lay science journalists – science is often complex and it is difficult to master the nuances if you are not an expert and steeped in the evidence and the community. Further there is a tendency for people in general (including journalists) to go along with an appealing and available narrative. (For journalists those narratives that are appealing are the ones that make good headlines.) These shortcomings are present throughout her recent article on placebos.

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Medicine is simultaneously both easy and hard. As an Infectious Disease doctor, my day can be summed up with the phrase “me find bug, me kill bug, me go home.” Sometimes it is just that simple. A lot of the time it isn’t. I may not be certain what the infection is, or even if the patient has an infection, or allergies and/or antibiotic resistance limit therapeutic options, the host has co-morbidities that limit effectiveness, and the patient has no financial resources for the needed treatment.

I am lucky, since most infections are acute, make people feel terrible, and require a relatively short course of therapy during which the patient feels better. I rarely have to worry about compliance with the treatment plan; it is the rare patient, usually a heroin user or a particularly irascible old man, who will not follow through with their antibiotic course. I do not have to worry about chronic or symptomless diseases like diabetes or hypertension or the complications of obesity where long term compliance often limit therapeutic success. Long term it is difficult for many people to stick with their therapeutic plan, much less their diet and exercise resolutions.
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In a previous post, I argued that placebo is an artifact of certain clinical interactions, rather than a treatment that we can exploit. Apparently, there are a whole lot of doctors out there who don’t agree with me. Or are there?

A recent study published in the British Medical Journal is getting
a lot of enk (e-ink) in the blogosphere. As a practicing internist, I have some pretty strong opinions (based in fact, of course) about both this study and placebos in general.

The Study

The current BMJ study defines placebo as “positive clinical outcomes caused by a treatment that is not attributable to its known physical properties or mechanism of action.”  I’ve got a lot of problems with this definition, but we’ll get to that later.  It also allowed physiologically active medications to “count” as placebos.  Oops.

The study surveyed internists and rheumatologists practicing in the U.S. They tried to control negative responses to the term “placebo” thusly (from the Methods section):

Because the term “placebo” and behaviours surrounding its use can be contentious, we devised a series of non-judgmental questions beginning with broad questions that avoided the term “placebo” and then gradually gained more specificity, culminating in items whose responses used a clear definition of a “placebo treatment.” By constructing a series of items in this manner we allowed respondents to describe their attitudes and experiences as accurately as possible.

The first set of three items began with a hypothetical scenario in which a dextrose tablet was shown in clinical trials to be superior to a no treatment control group (thus establishing its efficacy as a placebo treatment). To avoid biasing responses these three questions did not use the term “placebo,” “placebo treatment,” or “placebo effect.”

I know a lot of doctors.  They tend to be fairly bright.  I don’t think any of them would be deceived by this scenario.  When you read “dextrose pill”, you think “placebo”.  It might as well be the same word.

Respondents were then asked to indicate which of several treatments they had used within the past year primarily as a placebo treatment, defined as a treatment whose benefits derive from positive patient expectations and not from the physiological mechanism of the treatment itself; and how they typically described placebo treatments to patients. By asking these five questions both without the term “placebo” and then using the term, we aimed to assess physicians’ practices as accurately as possible.

All docs would recognize this as a placebo scenario.  However, the definition above is rather problematic.   Is a placebo “a treatment whose benefits derive from positive patient expectations and not from the physiologic mechanism of the treatment itself”?

The validity of this study hinges on the answer to this question.

Placebo—I do not think it means what you think it means

The concept of placebo, and the way it is used in this study are both problematic.  First, we have an elephant in the exam room.  When we observe a so-called placebo effect, we are very susceptible to the post hoc ergo propter hoc fallacy.  Just because the patient’s condition changes doesn’t mean we have done anything to cause that change.  In fact, due to the remarkably inexact human pattern-recognition software, we are likely to attribute a change in a patient’s condition to something, and if we don’t know what that something is, we may label it “placebo”.  So the very concept of placebo may be an artifact of our way of thinking, a label to place on a co-incidence, rather than a “thing”.  We may have wrongly reified a rather fuzzy concept.

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Towards the end of last week, I was contemplating what I would be writing about for Monday. No topic had quite floated my boat, but I hated to dip into the archive of topics I’ve written about before to update a post. After all, I like to be topical whenever possible. Then what to my wondering eyes should appear (yes, I know Christmas is still two months away) but a study in the British Medical Journal by a group lead by Jon C. Tiburt at the Department of Bioethics at the National Institutes of Health in collaboration with investigators at the Osler Institute at Harvard University and the McClean Center for Clinical Medical Ethics at the University of Chicago entitled Prescribing “placebo treatments”: results of national survey of US internists and rheumatologists.

Serendipity? Who cares? The study addresses a very important aspect of science-based medicine.
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In the Wall Street Journal last week was a particularly bad article by Melinda Beck about acupuncture. While there was token skepticism (by Edzard Ernst, of course, who is the media’s go-to expert for CAM), the article credulously reported the marketing hype of acupuncture proponents.

Toward the end of the article Beck admits that “some critics” claim that acupuncture provides nothing more than a placebo effect, but this was followed by the usual canard:

“I don’t see any disconnect between how acupuncture works and how a placebo works,” says radiologist Vitaly Napadow at the Martinos center. “The body knows how to heal itself. That’s what a placebo does, too.”

That is a bold claim, and very common among CAM proponents, especially acupuncturists. As the data increasingly shows that acupuncture (and other implausible treatments) provides no benefit beyond placebo, we hear the special pleading that placebos work also.

But is that true? It turns out there is a literature on the placebo effect itself, and the evidence suggests that placebos generally do not work.

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