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Archive for July 18th, 2011

Spin City: Using placebos to evaluate objective and subjective responses in asthma

As I type this, I’m on an airplane flying home from The Amazing Meeting 9 in Las Vegas. Sadly, I couldn’t stay for Sunday; my day job calls as I’ll be hosting a visiting professor. However, I can say—and with considerable justification, I believe—that out little portion of TAM mirrored the bigger picture in that it was a big success. Attendance at both our workshop on Thursday and our panel discussion on placebos on Saturday was fantastic, beyond our most optimistic expectations. There was also a bit of truly amazing serendipity that helped make our panel discussion on placebo medicine an even bigger success.

If there’s one thing about going away to a meeting, be it TAM or a professional meeting, it’s that it suddenly becomes very difficult for me to keep track of all the medical and blog stuff that I normally keep track of and nearly impossible to keep up with the medical literature. This is the likely explanation for why I had been unaware of a study published in the New England Journal of Medicine (NEJM) on Thursday that was so relevant to our discussion and illustrated out points so perfectly that it was hard to believe that some divine force didn’t give it to us in order to make our panel a total success.

Just kidding. It was TAM, after all. It was, however, embarrassing that I didn’t see the study until the morning of our panel, when Kimball Atwood showed it to me.

Before I get to the meat of this study and why it fit into our nefarious plans for world domination, (or at least the domination of medicine by science-based treatments), a brief recap of the panel discussion would seem to be in order. First, for the most part, we all more or less agreed that the term “placebo effect” is a misnomer and somewhat deceptive because it implies that there is a true physiologic effect caused by an inert intervention. “Placebo response” or “placebo responses” seemed to us a better term because what we are observing with a placebo is in reality a patient’s subjective response to thinking that he is having something active done having something done. In general, we do not see placebo responses resulting improvement in objective outcomes; i.e., prolonged survival in cancer. The relative contributions of components of this response, be they expectancy effects (if you expect to feel better you likely will feel better), conditioning, or one that is frequently dismissed or downplayed, namely artifacts of the design of randomized clinical trials and even subtle (or even not-so-subtle) biases in trial design. This issue of placebo responses being observed only in subjective patient-reported clinical outcomes (pain, anxiety, and the like) and not in objectively measured outcomes is an important one, and it is one that goes to the heart of the NEJM study that so serendipitously manifested itself to us. As Mark Crislip so humorously pointed out, the placebo response is the beer goggles of medicine (this is not a spoiler or stealing Mark’s line; several TAM attendees have already tweeted Mark’s line), and much of what is being observed are changes in the patient’s perception of his symptoms rather than true changes in the underlying pathophysiology. This study drove the point home better than we could.

Another point discussed by the panel is also quite relevant. As more and more studies demonstrate very convincingly that “complementary and alternative medicine” (CAM) or “integrative medicine” (IM) therapies do not produce improvements in symptoms greater than placebo. Moreover, multiple studies, including a famous NEJM meta-analysis and a recently updated Cochrane review, demonstrate, placebo responses probably do not constitute meaningful responses. In light of these findings, CAM apologists, driven by ideology rather than science and masters of spin, have begun to admit grudgingly that, yes, in essence their treatments are elaborate placebos. Not to be deterred, instead of simply concluding that their CAM interventions do not work, they’ve moved the goal posts and started to try to argue that it doesn’t matter that CAM effects are placebo effects because placebos are “powerful” and good and—oh, yes, by the way—there are a lot of treatments in science-based medicine that do little better than placebos. In other words, CAM advocates elevate the subjective above the objective and sell the subjective, and that’s exactly what they are doing with this study.
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Posted in: Acupuncture, Clinical Trials, Medical Ethics

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