Earlier, I was lamenting the state of modern healthcare, and arguing that a lot of tests and procedures ordered by doctors are done more in the interest of the doctor padding their wallet than out of necessity. (In many situations doctors are reimbursed by the cost/complexity of the procedure.) Specifically, I noted two surgical procedures that had been performed on people I know with no apparent benefit.
Now, you can say, “Fine, Wil. Some surgeries fail. But many surgeries succeed, showing that they are indeed useful.” In reply, I will first stew in the corner, red-faced at your insurrection. I will then state that, yes, many surgeries do seem to have value. But perhaps not for the reasons we assume.
The placebo effect is a commonly understood notion. It’s the idea that something with no medicinal or therapeutic value (a water pill, for example) can have some kind of positive effect. Though it’s certainly a controversial idea, many medical authorities do recognize the placebo effect, partly because it makes their job more difficult. If you have a new pill to test, even if you do double-blind studies, you still have to wonder, “Did the pill actually work? Or was it that damned placebo effect?”
So what does this have to do with surgeries? The book I’m reading, “The Cure Within,” revisits an article from the New York Times Magazine called “The Placebo Prescription,” which had a fascinating anecdote. The story goes…
In the early 1990s, a surgeon by the name of Bruce Moseley persuaded his hospital to allow him to conduct a placebo-controlled trial of a common form of arthroscopic knee surgery. Surgical techniques are rarely subjected to controlled trials since the inherent risks of surgery are considered too great to justify asking patients to submit to them without clear benefit. Nevertheless, in this instance Moseley prevailed. Patients were recruited for a trial and then divided into two groups. One group underwent the usual surgical procedure. The other group was subjected to all the paraphernalia and theater of a real operation, but Moseley actually did not cut, scrape, or do anything therapeutic to their knees at all — he just open them up and then closed them again. He himself did not know whether or not he would be “really” operating until he opened an envelope in the operating theater. What was astonishing about all this was that the patients who received fake treatment improved: not just briefly or subjectively, but on multiple measures of objective function. Even after they were told they had received placebo version of the surgery, they continued to walk better, declared they slept more soundly, reported they were able to mow the lawn again, and more.
Fascinating stuff. But perhaps not enough to convince everyone. And, in fact, the website skepdic.com criticizes Moseley’s experiment.
Typical of the kind of flawed research methodology Hróbjartsson is referring to would be that of surgeon J. Bruce Moseley who performed fake knee surgery on eight of ten patients. (Fake surgery involves making an incision on the knee and stitching it up.) Six months after the surgery all the patients were satisfied customers. Rather than conclude that the patients didn’t need surgery or that the surgery was useless because in time the patients would have healed on their own, he and others concluded that the healing of the eight who did not have surgery was due to the placebo effect, while the two who had real surgery were better because of having had the operation.
Where lies the truth? I don’t know. But one point would be true in both the placebo effect scenario, and the “healed on their own” scenario: surgery was not really necessary, or least it did not work the way it was presumed to.
Now, if your doctor recommends that you have surgery for some ailment, am I saying you shouldn’t have it? No, of course not. It’s your decision. But I would recommend thinking critically before making a commitment.
I’ve written previously about the placebo effect, here.