Let us suppose we have a treatment and we want to find out if it works. Call this treatment drug X. While we have observational data that it works—that is, patients say it works or, that it appears to work given certain tests—observational data can be misleading. As Edzard Ernst writes:
Whenever a patient or a group of patients receive a medical treatment and subsequently experience improvements, we automatically assume that the improvement was caused by the intervention. This logical fallacy can be very misleading […] Of course, it could be the treatment—but there are many other possibilities as well.
So we decide to hold a Randomised Control Trial (RCT). An RCT takes account for the non-specific effects of the treatment—these misleading possibilities Ernst is so interested in. The RCT has three arms to the experiment: the first arm receives the active treatment (in our case, drug X); the second arm receives a placebo, a treatment which mimics the drug X except in that it is devoid of the active ingredients (in our case, it’ll be a sugar pill); the third arm receives no treatment whatsoever. Following the RCT, we’ll know: first, whether the treatment is doing anything at all; and second, whether or not it is the active elements of the treatment that are doing the work.
The results of our RCT say that the first and second arms of the treatment are effective (that is, those patients receiving drug X and the sugar pill); however, there doesn’t appear to be any difference between those patients receiving drug X and those receiving the sugar pill. Standardly we would say, only when the active treatment shows improvement over and above the placebo, can we call the treatment effective. Does drug X work? No.*
However, there’s a more fundamental question that remains: if drug X makes patients better, why shouldn’t we give it to them? Standard arguments against giving non-affective treatments include, inter alia: it is akin to deception; it closes the door to any other possible treatment (for at least a considerable amount of time) that may show effects over and above simply the therapeutic effect; and the treatment may conflict with other treatments. On the other hand, recently Jonny Pugh (of this very blog) has suggested that, in some circumstances, knowingly giving placebos is permissible. He writes:
First, the GP must prescribe the placebo with the intention of promoting her patient’s ends rather than her own, and she must be justified in holding the belief that the patient would value the amelioration of his condition over holding true beliefs about his treatment. Second, the prescribing physician must be justified in believing that a placebo is a necessary means of promoting the patient’s health.
Offhand, most people seem to think that where other treatments aren’t possible, what’s the harm?!
I don’t want to get engaged with these debates. Rather, I’d like to propose a different argument. To do so I will borrow from the work of Allan Buchanan. Buchanan distinguishes between two different kinds of trust: status-trust is conferred to persons on the grounds of having a certain status or being the member of a certain group; merit-trust is based on individual performance (most commonly, on past performances realised as qualifications). Status-trust is desirable because it allows for the benefits of the division of epistemic-labour, operating much like a brand name in the market: it tells us which people I can trust and which people I shouldn’t. Doctors have both status-trust and merit-trust. Accordingly, we generally defer to their judgments concerning medical issues.
Here’s my problem. When a doctor tells a patient that drug X works, we believe them. The issue comes, however, when drug X belongs to a family of treatments that do not work. For instance, let us suppose that drug X is a complimentary or alternative medicine, much like Reiki in the actual case I am borrowing from or a homeopathic treatment. The problem is that, while taking drug X may not harm us if there are no other treatments available, a doctor telling me that drug X works may also have the affect of making me think that the family of drugs to which it belongs also works (or, maybe even that since this alternative family of drugs work, all alternative families of drugs work). This problem will be heightened if, as many believe, placebos only work when the patients are unaware they are receiving a placebo—and thus, it will be hard for the doctor to try and stop these inferences from taking place.
Let me apply this to practice. Suppose we have a homeopathic treatment X to treat condition Y. There are no other treatments that treat condition Y. Treatment X does not actively treat condition Y.** It does, however, make the patient feel a little better (because of the therapeutic-placebo affect). While this may not be objectionable in itself, because of the status-trust I have to my doctor, I may think that homeopathy works in a principled way (rather than that this homeopathic treatment works). I may think that all alternative medicine’s work. This is, by all means, an empirical claim I am making; but it is one I feel comfortable making (people often reply to my questioning of homeopathy by saying, ‘but can’t you can get it on the NHS!’). With respect to complimentary and alternative medicine, the doctor will not be able to prevent patients from drawing an inference that the family of treatments work: I simply cannot see how a doctor could say ‘this homeopathic medicine works, but homeopathy generally doesn’t work’, as this would seem conflicted. Rather, the doctor will have to say homeopathy works.
And, thinking theses sorts of things may be harmful.
Ernst, ‘Giving placebos such as reiki to cancer patients does more harm than good’, http://www.theguardian.com/science/blog/2011/oct/11/placebos-reiki-cancer-patients-harm
— ‘Why I changed my mind about homeopathyh’, http://www.theguardian.com/science/blog/2012/apr/03/homeopathy-why-i-changed-my-mind
** I am now comfortable believing that homeopathy gains its effectiveness from the therapeutic placebos effect. For example, see Ernst, ‘Why I changed my mind about homeopathyh’. For those unconvinced that homeopathy doesn’t work, please sub in a treatment that one agrees doesn’t work and the argument should still apply.
*This example mimics an RCT spoken about by Ernst in 2011 to determine the therapeutic affects of Reiki for patients receiving chemotherapy.
In 2011 a RCT was designed to determine the effectiveness of Reiki therapy in regard to comfort and well-being in chemotherapy outpatients. Reiki is a system of natural healing originating in 1920’s from Japan. It involves channelling “healing energy” into the body. ‘Lots of people swear by it, but does it really work?’ (Ernst)
To answer this question, the double-blind RCT had three arms where the 189 participants were randomly treated with actual Reiki, a “sham” Reiki placebo and standard care. The control group, or “sham” Reiki consisted of a non-Reiki healer who was not trained in Reiki but did follow the ritual of the treatment. ‘So he did not send any ‘healing energy’ to the patients whereas the Reiki healer had been taught to do just that’ (Ernst)
The findings were that although Reiki therapy was statistically significant in raising the comfort and well-beings of the patients, the placebo or “sham” Reiki showed essentially the same statistical significance. Patients in the control standard care group saw no change.
These results could be interpreted in two ways. As Ernst cites, the nurses who ran the trail concluded that Reiki does increase patient comfort and well-being. Whereas Ernst, and myself, would conclude that ‘genuine Reiki is no better than sham Reiki, thus it does not work.’ What the trial does show is that providing one-on-one support during chemotherapy was influential in improving comfort and well-being, regardless of “healing energy”.
I suppose the Dr could truthfully say, “the best treatment we have available for your condition is drug X. However, for your other ailment, whilst drug Y (from the same family as X) is effective [since presumably placebo effect would still apply so it is truthfully better than nothing], there are more effective alternates”
In a way it would function in the same way as newer more effective medicines replacing older less effective ones.
The interesting thing here is that taking placebos can make a difference. (As acknowledged in the post.)
So “prescribing what you think are placebos” may be effective.
It can be argued that humans can heal themselves with their minds. That placebo relies on that.
This would seem to warrant some research. If we can sometimes cure ourselves with our own minds, knowing that may be useful.
I think the fact that it may be useful is a problem for prescribers and those who benefit from prescriptions. Have they influenced this blind spot in thinking.
The premise of this debate that placebos do nothing may be flawed.
“This problem will be heightened if, as many believe, placebos only work when the patient are unaware they are receiving a placebo”
I assume this has more to do with the definition of “placebo” than with actual tested results. If you tell people they’re receiving a placebo, then they’re no longer receiving a placebo – it would be a “sham placebo”. But I wonder if there have been any controlled tests between groups receiving placebos and groups receiving sham placebos. The latter could be told before the test that placebos are effective in a certain percentage of cases, lower than that of treatments with effective active ingredients, but higher than no treatment at all, and that the point of the test is to see whether this remains the case when the patients are aware that their medication has no active ingredients. If tests of this kind were to show that sham placebos are as effective as real ones, it would presumably change the nature of the debate.
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