Confessions of a Quackbuster

This blog deals with healthcare consumer protection, and is therefore about quackery, healthfraud, chiropractic, and other forms of so-Called "Alternative" Medicine (sCAM).

Tuesday, January 18, 2005

The Placebo Illusion

Is the placebo effect as strong as often proposed? Is it ethical to use it in clinical practice? How much is hype and how much is fact?

The placebo effect is always present, including in legitimate methods. The degree of subjectivity involved determines to what degree it manifests itself. It has practically no influence on purely objective physiological phenomena, but is active to some degree in subjective results.

Someone on a discussion list wrote:

> The late Patrick Wall estimated that placebo
> effect accounted for 0-100% of outcomes in
> a given study.

This is too general. To use percentages, we could make a scale from 0-100%, and place the objective factors at the 0% end and the subjective factors at the 100% end. Objective factors would show little or no percentage of effect from placebo, and subjective factors would have more, but not (or rarely) even approaching 100%.

The latest research reduces the placebo effect to a subjective illusion (IOW getting fooled and deceived), and a research/statistical tool. As such it is imperative to use it in research, but unethical to use it in treatment.

The results of this research contradict what should now be considered a great deal of folklore that has evolved around the whole idea:


"The pooled standardized mean difference was significant for the trials with subjective outcomes but not for those with objective outcomes. In 27 trials involving the treatment of pain, placebo had a beneficial effect, as indicated by a reduction in the intensity of pain of 6.5 mm on a 100-mm visual-analogue scale.

"Conclusions. 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."

(N Engl J Med 2001;344:1594-602.) -- Gøtsche

The key words here are "subjective" and "pain". That's why the placebo effect is most "effective" in conditions where the subjective factors are most often prominent or significant parts of the problem: headache, stomach ache, asthma, allergy, tension, and especially the most subjective of them all - pain.

While all of these problems can have very real, biological factors for which placebo has no effect, they are also often accompanied by complex psychological mechanisms which respond to placebo inducing factors: deception and self-deception, caring, touching, sympathy, etc.

Curiously....(logically!!) . . . ;-) these are the same conditions that respond best to most sCAM modalities: acupuncture, reflexology, homeopathy, etc. IOW, sCAM is good for it if it's mostly "all in your head", but more or less worthless if it's really in your body.

Which means that sCAM is worse than worthless when it prevents you from seeking real EBM help for real biological problems.

CAM COSTs!! It is just an added expense and a potentially dangerous diversion and detour:

Let's face it:

Placebo tricks the mind and sCAM tricks the patient. They are both frauds, which is the whole idea. An illusion isn't believable if it is known to be an illusion. A sucker is born every minute......

I agree with one of the conclusions in the article: Placebo should be reserved for clinical trials, where deception is implicitly allowed, in fact is essential, but it has no place in treating patients, where deception would be unethical.

We have enough difficulty in the whole healthcare system with evidence-basing our *existing* practices. The things we *currently* do, which (using extremely well-controlled research) turn out to have no better effect than the "placebo illusion" (it is, after all, only a subjective effect and a statistical research tool - see Gøtsche above) must be discarded.

There are methods currently in use - with a long history of acceptance within legitimate modern medicine - but without a good research base. They should not be abandoned for this reason. Before such drastic steps are taken, they should be extremely thoroughly researched. If such research proves that they absolutely have no value or effect above and beyond the placebo effect, they should be abandoned. But not before then.

Evidence-based methods are effective, and effective methods should be evidence-based. If a method appears to be effective, then it should be possible to prove it. If the research has not been done yet, it should be. We must remember that 'Absence of proof is not the same as the absence of fact; it simply demonstrates the lack of adequate research.' - Robert Sydenham. 'Lack of evidence in the literature is not evidence of lack of effectiveness.'

Since EBM is a process that is partially based on what we have learned from past errors, all methods that seek to *become* included in the healthcare system's toolbox of methods, must be evidence-based thoroughly *before* their acceptance. (The popularity or age of the method is irrelevant here. Lots of nonsense has been practiced for thousands of years, and enjoyed lots of popularity.)

EBM is a process that seeks to analyze and evidence-base *all* methods. Those that pass the test eventually get accepted and used, and those that It's a sorting process designed to purify the system of *existing* pollution, and to keep it free from pollution in the *future*.

It is this process that separates modern medical practice from so-Called "Alternative" Medicine (sCAM), because sCAM *never* abandons a method, even after it has been thoroughly disproven.

Much quackery achieves temporary "success" by a conscious or unconscious misuse of the placebo illusion. It can be fatal.

Here's what Randi has to say:

5) What harm does it do to simply let people believe in silly things? Why do you take away their pleasant delusions?

The potential harm is very real, and dangerous. Belief in such obvious flummeries as astrology or fortune-telling can appear quite incorrectly to give confirmatory results, and that can lead to the victim pursuing more dangerous, expensive, and health-related scams. Blind belief can be comforting, but it can easily cripple reason and productivity, and stop intellectual progress. We at JREF never try to impose our beliefs or philosophy on others; we only try to inform them, and suggest that there are alternate choices to be made. Examples of personal tragedies resulting from an uncritical embrace of supernatural claims, are plentiful.

"It's a very dangerous thing to believe in nonsense." -- James Randi.

Dr. Greeno's comments are very appropriate here:

The answer to this issue depends somewhat on what is meant by a placebo response. The Danish study cited below indicates a lack of data for a physiologic placebo response; i.e., an improvement of some objective measure of a disease state. However, inumerable studies in which the endpoint is a subjectively reported symptom (e.g., look back at the series of acupuncture studies we've discussed here in the past few months that have included very "effective" sham treatments), do seem to demonstrate a clear placebo "response". In other words, a placebo can make you think you are better, but won't actually make you any better--which sounds an awful like the state of affairs with CAM therapies. -- Edward Greeno, MD

Since homeopathy is the ultimate placebo, take a look at this:

Homeopathic Booze?

There are many other phenomena that are often included in statistics as though they were part of the placebo effect, when in fact they are distinct phenomena. This page lists a number of them: