Has it ever occurred to you that much of the discussion about cause and effect in alternative medicine goes in circles without ever making progress? I have come to the conclusion that it does. Here I try to illustrate this point using the example of acupuncture, more precisely the endless discussion about how to best test acupuncture for efficacy. For those readers who like to misunderstand me I should explain that the sceptics’ view is in capital letters.
At the beginning there was the experience. Unaware of anatomy, physiology, pathology etc., people started sticking needles in other people’s skin, some 2000 years ago, and observed that they experienced relief of all sorts of symptoms.When an American journalist reported about this phenomenon in the 1970s, acupuncture became all the rage in the West. Acupuncture-fans then claimed that a 2000-year history is ample proof that acupuncture does work.
BUT ANECDOTES ARE NOTORIOUSLY UNRELIABLE!
Even the most enthusiastic advocates conceded that this is probably true. So they documented detailed case-series of lots of patients, calculated the average difference between the pre- and post-treatment severity of symptoms, submitted it to statistical tests, and published the notion that the effects of acupuncture are not just anecdotal; in fact, they are statistically significant, they said.
BUT THIS EFFECT COULD BE DUE TO THE NATURAL HISTORY OF THE CONDITION!
“True enough”, grumbled the acupuncture-fans and conducted the very first controlled clinical trials. Essentially they treated one group of patients with acupuncture while another group received conventional treatments as usual. When they analysed the results, they found that the acupuncture group had improved significantly more. “Now do you believe us?”, they asked triumphantly, “acupuncture is clearly effective”.
NO! THIS OUTCOME MIGHT BE DUE TO SELECTION BIAS. SUCH A STUDY-DESIGN CANNOT ESTABLISH CAUSE AND EFFECT.
The acupuncturists felt slightly embarrassed because they had not thought of that. They had allocated their patients to the treatment according to patients’ choice. Thus the expectation of the patients (or the clinician) to get relief from acupuncture might have been the reason for the difference in outcome. So they consulted an expert in trial-design and were advised to allocate not by choice but by chance. In other words, they repeated the previous study but randomised patients to the two groups. Amazingly, their RCT still found a significant difference favouring acupuncture over treatment as usual.
BUT THIS DIFFERENCE COULD BE CAUSED BY A PLACEBO-EFFECT!
Now the acupuncturists were in a bit of a pickle; as far as they could see, there was no good placebo for acupuncture! Eventually some methodologist-chap came up with the idea that, in order to mimic a placebo, they could simply stick needles into non-acupuncture points. When the acupuncturists tried that method, they found that there were improvements in both groups but the difference between real acupuncture and placebo was tiny and usually neither statistically significant nor clinically relevant.
NOW DO YOU CONCEDE THAT ACUPUNCTURE IS NOT AN EFFECTIVE TREATMENT?
Absolutely not! The results merely show that needling non-acupuncture points is not an adequate placebo. Obviously this intervention also sends a powerful signal to the brain which clearly makes it an effective intervention. What do you expect when you compare two effective treatments?
IF YOU REALLY THINK SO, YOU NEED TO PROVE IT AND DESIGN A PLACEBO THAT IS INERT.
At that stage, the acupuncturists came up with a placebo-needle that did not actually penetrate the skin; it worked like a mini stage dagger that telescopes into itself while giving the impression that it penetrated the skin just like the real thing. Surely this was an adequate placebo! The acupuncturists repeated their studies but, to their utter dismay, they found again that both groups improved and the difference in outcome between their new placebo and true acupuncture was minimal.
WE TOLD YOU THAT ACUPUNCTURE WAS NOT EFFECTIVE! DO YOU FINALLY AGREE?
Certainly not, they replied. We have thought long and hard about these intriguing findings and believe that they can be explained just like the last set of results: the non-penetrating needles touch the skin; this touch provides a stimulus powerful enough to have an effect on the brain; the non-penetrating placebo-needles are not inert and therefore the results merely depict a comparison of two effective treatments.
YOU MUST BE JOKING! HOW ARE YOU GOING TO PROVE THAT BIZARRE HYPOTHESIS?
We had many discussions and consensus meeting amongst the most brilliant brains in acupuncture about this issue and have arrived at the conclusion that your obsession with placebo, cause and effect etc. is ridiculous and entirely misplaced. In real life, we don’t use placebos. So, let’s instead address the ‘real life’ question: is acupuncture better than usual treatment? We have conducted pragmatic studies where one group of patients gets treatment as usual and the other group receives acupuncture in addition. These studies show that acupuncture is effective. This is all the evidence we need. Why can you not believe us?
NOW WE HAVE ARRIVED EXACTLY AT THE POINT WHERE WE HAVE BEEN A LONG TIME AGO. SUCH A STUDY-DESIGN CANNOT ESTABLISH CAUSE AND EFFECT. YOU OBVIOUSLY CANNOT DEMONSTRATE THAT ACUPUNCTURE CAUSES CLINICAL IMPROVEMENT. THEREFORE YOU OPT TO PRETEND THAT CAUSE AND EFFECT ARE IRRELEVANT. YOU USE SOME IMITATION OF SCIENCE TO ‘PROVE’ THAT YOUR PRECONCEIVED IDEAS ARE CORRECT. YOU DO NOT SEEM TO BE INTERESTED IN THE TRUTH ABOUT ACUPUNCTURE AT ALL.