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Behold the spin! What a new survey of placebo prescribing really tells us

One of the recurring topics here at SBM is the idea of the placebo: What it is, what it isn’t, and how it complicates our evaluation of the scientific evidence. One my earliest lessons after I started following this blog (I was a reader long before I was a writer) was that I didn’t understand placebos well enough to even describe them correctly. Importantly, there is no single “placebo effect”. They are “placebo effects”, a range of variables that can include natural variation in the condition being studied, psychological factors and subjective effects reported by patients, as well as observer bias by researchers studying a condition. All of these, when evaluated in clinical trials, produce non-specific background noise that needs to be removed from the analysis. Consequently, we compare between the active treatment and the placebo to determine if there are an incremental benefits, to which we apply statistical tests to determine the likelihood that the differences between the intervention and the placebo groups are real. Removed from the observational nature of the clinical trial, we can’t expect the observed “placebo effects” to persist, as they’re partially a consequence of the trial itself. A more detailed review of placebos is a post in and of itself, so I’ll refer you to resources that describe why placebo effects are plural, that placebo effects are subjective rather than objective and there is no persuasive evidence to suggest that placebo effects offer any health benefits. What’s most important is the understanding that placebo effects are a measurement artifact, not a therapeutic effect.

Placebo effects are regular topics within in SBM posts because an understanding of placebo effects is essential to evaluating the evidence supporting (so-called) complementary and alternative medicine, or CAM. As better quality research increasingly confirms that the effects from CAM are largely, if not completely, attributable to placebo effects, we’ve seen the promoters of CAM shifting tactics. No longer able to honestly claim that CAM has therapeutic effects, “treatments” such as acupuncture or homeopathy are increasingly promoted as strategies that”harness the power of placebo” without all the pesky costs or side effects of real medical interventions. But this is simply special pleading from purveyors and promoters. Unable to wish away the well-conducted trials that show them to be indistinguishable from placebos, they instead are spinning placebo effects as meaningful and worthy of pursuit – ideally with your favourite CAM therapy. Again, I’ll refer you to posts by David Gorski and Steven Novella who offer a more detailed description of how negative results can be spun to look positive. Because CAM’s effects are indistinguishable from placebo, we should not invest time and resources into pursuing them – we should instead focus on finding treatments that are demonstrably superior to placebo.

But what if physicians are already using placebos widely in practice? Setting aside the ethical issues for now, widespread placebo usage might suggest that physicians believe that placebos are effective treatments. And that’s the impression you may have had if you skimmed the medical headlines last week:

97 percent of UK doctors have given placebos to patients at least once said the press release

Doctors like to ‘sugar the pill’ said The Express

Most doctors prescribe placebos – said The Telegraph

Probing the power of placebos – The Globe and Mail

All of this comes from survey published published in PLOS ONE last week, Placebo Use in the United Kingdom: Results from a National Survey of Primary Care Practitioners. Before diving into the findings, let’s consider the context of placebo use – not in clinical trials, but in the real world.

Is it a placebo in the eye of the prescriber?

The deliberate use of inert therapies in medicine is not a new topic and has been covered before at SBM. Like other contributors to this blog, I find the idea of actively prescribing placebos to be both unethical and highly paternalistic. Why jeopardize patient trust? Back in 2011 I summarized the evidence on the prevalence of placebo prescribing. But to understand the data we need to define “placebo” when it’s being used outside a clinical trial. Not every placebo is a sugar pill, and not every placebo is used with “placebo” intent. There are two forms of placebo in routine medical use: “Pure” placebos are truly inert: they contain no medicinal ingredients. These are the sugar pills, saline injections, and most homeopathic “remedies”. They’re the products we used in clinical trials when it’s “placebo-controlled.” “Impure” placebos, on the other hand, actually contain medicinal ingredients, but are ineffective for the condition being treated. This could be because of a sub-therapeutic dose, or the active ingredient has no effectiveness against the condition being treated (e.g., antibiotics for viral infections). We don’t use impure placebos in clinical trials, as there’s the risk it could cause its own effects or adverse events. Pure or impure, a placebo must be ineffective for the condition being treated – otherwise it’s not a placebo.

There is a lack of good data that summarizes on how routinely placebos are deliberately prescribed. A 2010 paper provides the most comprehensive summary, and the findings are complicated by inconsistent questions, changing definitions of what a placebo actually is, and other study design problems. Consequently the results of reported placebo use by physicians varies: 17-80% for pure placebos, and 41-99% for impure placebos, in response to “have you ever prescribed” questions. But few physicians use placebos regularly, and “impure” placebos are used far more frequently used than “pure” placebos. Which is understandable, as prescribing antibiotics for what’s likely (but not unequivocally) a viral infection should be more common than the deliberate use of sugar pills and deception to make a patient think they’re getting medicine when they’re not.

So let’s take a closer look at the most recent study, the one that generated all of the headlines. As it’s at PLOS ONE, the full text is available. The lead author was Jeremy Howick, a PhD scientist, and the study was funded by The University of Oxford Department of Primary Care Health Sciences and The Southampton Complementary Medical Research Trust. “Complementary”? Howick writes under the name “Dr. Placebo” at trusttheevidence.net, and his writing suggests that he believes placebos have physiologic effects. In fact, Howick goes so far as to suggest that given the side effects of real drugs, “not prescribing placebos might be even less ethical.” Another of the coauthors is George Lewith, a “complementary medicine” physician who has published research on homeopathy and is a proponent of “integrative” healthcare. Lewith has an equally interesting perspective on the use of placebos in clinical practice, one that we’ll come back to, when we interpret the findings of the survey and the conclusions drawn by the authors.

This was a web-based survey of over 1700 general practitioners registered with a marketing service. 783 completed the questionnaire, which is an fair response rate for a survey, but could bias the sample towards those interested in placebos. The sample that responded was 55% male, in practice for an average of 20 years – so these were not new graduates. The way the authors describe the rationale for the study belies their interest “complementary” medicine:

Since this was an empirical rather than conceptual study we adopted a pragmatic approach and asked doctors whether they used various treatments described as placebos in other similar surveys. Our approach has the advantage of being useful: patients, doctors, and policy makers care more about whether particular treatments are effective and ethical than whether these treatments carry the label ‘placebo’.

Rather than useful, the “pragmatic” approach they used gives results that are the opposite of useful – they’re highly biased. As I noted above, the systematic review by Fässler illustrates that different definitions of “placebo” can have a significant influence on the results reported. To their credit, the authors use a “pure placebo” definition that’s consistent with other studies: “sugar pills or saline injections without direct pharmacologically active ingredients for the condition being treated.” But their definition of “impure placebo” is so expansive that it’s not clear to me that the authors understood what an “impure placebo” is supposed to be:

  • Positive suggestions
  • Nutritional supplements for conditions unlikely to benefit from this therapy (such as vitamin C for cancer)
  • Probiotics for diarrhea
  • Peppermint pills for pharyngitis
  • Antibiotics for suspected viral infections
  • Sub-clinical doses of otherwise effective therapies
  • Off-label uses of potentially effective therapies
  • Complementary and Alternative medicine (CAM) whose effectiveness is not evidence-based
  • Conventional medicine whose effectiveness is not evidence-based
  • Diagnostic practices based on the patient’s request or to calm the patient such as
    • Non-essential physical examinations
    • Non-essential technical examinations of the patient (blood tests, X-rays)

There are some reasonable inclusions. Subclinical doses are also appropriately categorized as “impure” placebos, as are products that are ineffective for the condition being treated (e.g., antibiotics for suspected viral infections). But there are some odd entries, too.

Positive suggestions are considered an “impure placebo” yet they can be part of routine patient encounters and not offered with deliberate placebo intent. I give positive suggestions to patients routinely when I reassure them their cold is self-limiting and will resolve in few days, medicated or not. This isn’t an “impure placebo”. Probiotics for diarrhea lack a strong evidence base but may not be given with placebo intent, as practitioners may believe they are effective. Bizarrely, all off-label drug use is considered “placebo”, suggesting either the authors have very little practical knowledge of medical practice, or are deliberately trying to widen the category of “impure placebo”. Off-label use means a drug is unapproved for the intended use. It does not indicate there is a lack of evidence, only that a regulator hasn’t formally approved use. When drugs are used for niche purposes (e.g., pediatric prescribing or rare diseases) pharmaceutical manufacturers may not bother seeking regulator approval. Bizarrely, they also include “conventional medicine whose effectiveness is not evidence based” as a separate category. Finally, the inclusion of CAM “whose evidence is not evidence-based” is telling. CAM which is evidence-based isn’t CAM any more – it’s simply medicine. And ineffective CAM may not be a placebo, as ineffective doesn’t mean safe, or free of side effects. Diagnostic practices are also included here as “impure placebos” which stretches the definition of what a a placebo is. Physical exams are not placebos – they may be used to rule out a diagnosis or to reassure a patient about the certainty associated with a diagnosis. They’re not expected to have therapeutic effects, but may be done to comfort patients, or reassure them of the diagnosis. Similarly, lab tests are not “placebo” treatments – no-one expects a therapeutic benefit from an X-ray, but may be reassured by the results. They may be completely unnecessary, but they’re not a therapeutic placebo. Again – a placebo must be ineffective for the condition being treated – otherwise it’s not a placebo.

To their credit, the investigators did offer respondents the opportunity to indicate that an intervention was “not a placebo”. But on the primary question of placebo use, we should expect the use of impure placebos to be off the charts. And that’s exactly what we see in the results. Here’s the results to the primary question:

Table 1: Summary of placebo Usage

12 % reported using pure placebos at least once in their career and 97% reported using impure placebos at least once. Given the definitions, it should not be surprising that nearly every physician has used what the authors defined as an “impure” placebo at least once.

When we break down the placebo use, the results are a bit more useful:

Frequency of Placebo Use by Type of Placebo

The frequency at which pure placebos are used frequently or occasionally is very low – consistent with other studies. 97.4% use pure placebo less than once per year, or have never used a pure placebo.

The breakdown of “impure” placebo is much more interesting than what the headlines reported. Not surprisingly, positive suggestions were the most commonly reported (71% reporting frequent or occasional use) with 11% indicating it wasn’t a placebo at all. Beyond that, few were used frequently with the exception of antibiotics for suspected viral infections (75% saying frequently or occasionally) and medicine used in a non-evidence-based way (77%). Non-essential physical exams were the most common non-therapeutic offered (54% reporting frequently), but again, I don’t feel this is a placebo treatment – but only 5% of physicians apparently agreed with me.

Then there’s the “other” category which again left me wondering what isn’t considered a placebo in this study, as cognitive behavioural therapy, iron tablets, physiotherapy, reassurance and even “referral to website” are included as well.

Finally physicians were asked a series of questions about situations where placebo use would be considered acceptable and unacceptable:

Table 3. Summary of practitioner beliefs about ethical acceptability of placebo use.

Physicians were largely split on their acceptability of placebo for psychological effects, or when “the patient wants or expects this therapy”. In response to their acceptability “when clinical experience has shown a benefit” seems carefully worded to dodge the reality of placebo and instead appeal to anecdotes – “clinical experience”. In this case, the reported acceptability climbs to 60% for pure placebos and 79% for impure placebos. Reassuringly, there were strong opinions that placebos are not acceptable when they involve deception or may jeopardize patient trust. Perhaps not surprisingly the authors call these ethical constraints “perhaps sometimes unjustified” in the discussion section of the paper.

A nation of placebo prescriptions?

The authors go for the headlines and paint a picture of widespread placebo use in their discussion of the results:

Placebos may represent one of the more commonly used treatments in UK primary care in spite of (perhaps sometimes unjustified) ethical constraints. Twelve percent of respondents reported using pure placebos, and 97% reported using impure placebos at least once in their career. Many placebos were used frequently by over half the respondents, and most general practitioners felt there were circumstances in which impure and pure placebos were ethically acceptable. Half of the practitioners who use placebos informed their patients that this intervention has helped other patients without specifically telling them that they were prescribing a placebo. This raises unresolved ethical issues about how GPs approach informed consent in relation to their prescriptions of placebos.

My interpretation is a bit different. The survey was explicitly designed to make placebo use appear widespread. A closer look suggests that physician behavior is more nuanced and circumspect than what the headlines suggested. Regular prescribing with pure placebos is exceptioanlly rare. Physicians agree that they are not acceptable when they involve deception or endanger patient trust. In some situations, they feel they’re acceptable. But this clearly seems to be the exception, rather than the rule. On balance, it’s what I’d expect in a physicians or health professional.

However, given the background of the authors, and their interest in promoting the active use of placebo treatments, the paper has a different conclusion:

The time has come to use similar methods to investigate ways to rationalize placebo use. The long term viability of placebo use in clinical practice depends on whether placebo benefits outweigh harms, their cost, and whether patients and practitioners deem their use to be ethically acceptable. Further investigations are warranted to develop ethical and cost-effective placebos.

I’m sure the authors have some ideas about just what those ethical and cost-effective placebos might be. The design and results seem perfectly designed to position the use of CAM to generate what they believe are clinically relevant placebo effects. In media quotes, the intent is obvious:

“This is not about doctors deceiving patients,” said Dr Jeremy Howick, co-lead author of the study from the University of Oxford. The study shows that placebo use is widespread in the UK, and doctors clearly believe that placebos can help patients.”

Professor George Lewith, co-lead author of the study from the University of Southampton, said: “Other previous published studies by Southampton have clearly shown placebos can help many people and can be effective for a long time after administration. The placebo effect works by releasing our body’s own natural painkillers into our nervous system. In my opinion, the stigma attached to placebo use is irrational, and further investigation is needed to develop ethical, cost-effective placebos.”

The SKEPT!CAL blog ran the press coverage through the churnalism.com website and, disappointingly, found the media largely reported the press release nearly verbatim.

Conclusion

Given what appears to be an established interest by at least some of the authors in promoting the routine use of placebos and placebo treatments in medical practice, the design and results of this study should surprise no one. The survey was designed to give the impression of widespread, active placebo use by UK physicians. That’s what they found, that’s what they announced, and that’s what the media reported. The authors used this carefully designed argument from popularity to support their statements about the therapeutic legitimacy of placebo usage. Finally, add in some spin to suggest that placebo effects are therapeutically meaningful. And to what end? Because if physicians are already using placebos routinely, why not fund a few more – like…say…CAM? I’m sure the Southampton Complementary Medical Research Trust can think of a few products that might fit the bill.

The reality, of course, is quite different, and the survey results reflect this. Physicians use placebos relatively infrequently and generally recognize that they are unacceptable when they involve deception and jeopardize patient trust. Quite frankly, it’s not worth that risk. The most we can hope for when we use placebos are subjective reports of changes in a patient’s symptoms. Placebos have no objective, clinically meaningful effects. When a drug cannot be show to be more effective than placebo, we stop using the drug – we don’t repackage the placebo as a therapeutic agent. But that’s exactly what placebo proponents are proposing.

Reference

Howick J., Bishop F.L., Heneghan C., Wolstenholme J., Stevens S., Hobbs F.D.R., Lewith G. & Manchikanti L. (2013). Placebo Use in the United Kingdom: Results from a National Survey of Primary Care Practitioners, PLoS ONE, 8 (3) e58247. DOI:

Posted in: Clinical Trials, Epidemiology, Science and Medicine

Leave a Comment (24) ↓

24 thoughts on “Behold the spin! What a new survey of placebo prescribing really tells us

  1. FastBuckArtist says:

    Some patients have a condition that needs no treatment (like common cold) but they insist on getting a treatment.

    Placebos are given to send the patient away.

  2. rork says:

    ” ‘Current ethical rulings on placebos ought to be revisited in light of the strong evidence suggesting that doctors broadly support their use,’ says Dr Howick.” was a quote that floored me in an article I read a few days back about this.
    Ethics, schmethics, some docs wanting a thing is apparently the kind of evidence that matters, when there’s a lack of any other evidence.

  3. Earthman says:

    “…we apply statistical tests to determine the likelihood that the differences between the intervention and the placebo groups are real.”

    Scott, sorry to be picky but statistics never tell you anything is real, just that it is significantly different from random, or not.

  4. mousethatroared says:

    FastBuckArtist “Some patients have a condition that needs no treatment (like common cold) but they insist on getting a treatment.
    Placebos are given to send the patient away.”

    That’s not how my doctors work. If I go to the doctor (or take my children to the doctor) and their exam leads them to conclude that a self-limiting virus is at work, they typically give me advice on comfort measures and tell me to return if particular symptoms are not gone in X days.

    Of course, I don’t usually go to the doctor if I think the issue is a cold. Sometimes there are other viruses, though, that are pretty had for me to differentiate from an asthma flare or bacterial infection like strep or pneumonia. For me, the point is that I’m keeping the kids (or myself) safe. The point is not to get medication at any cost.

  5. kathy says:

    For anyone that enjoys dryyyyy British humour, take a look at this: http://www.aplacebo.com/

    The website is oh-so-believable if one is inclined towards true belief already. But the expression on the face of the rabbit says it all, and if you still doubt me, take the Quiz and you will see that this is a spoof a la Cambridge (Cambs not MA).

  6. mousethatroared says:

    This seems like one of the more bizarre studies that I have seen featured on SBM. The “impure placebo” group is such as hodge podge that it’s useless to try to get any real information out of it.

    Just a personal anecdote regarding non-essential diagnostic tests (quote) “They’re not expected to have therapeutic effects, but may be done to comfort patients, or reassure them of the diagnosis. Similarly, lab tests are not “placebo” treatments – no-one expects a therapeutic benefit from an X-ray, but may be reassured by the results. They may be completely unnecessary, but they’re not a therapeutic placebo. Again – a placebo must be ineffective for the condition being treated – otherwise it’s not a placebo.”

    When my son’s profound unilateral sensorineural hearing loss was discovered by his audiologist, they were unable to tell the cause by physical exam or audiology. We knew the loss was not treatable, but it may have been due to a malformation (or virus, etc). If a particular malformation was present bilaterally, he could eventual develop progressive hearing loss or become deaf in his good side. In that case, there were no preventative measures available.

    Our ENT gave us the option to have a CT scan, so that he could diagnose the cause of the hearing loss and we could see if the good side had malformations or was typical. He also informed us that there was no medical need for the CT scan since any possible progressive hearing loss was not preventable and his overall health was not in question. On the other hand the information might be useful in making educational or communication decisions for our child.

    We did have the test and it turned out that my son’s good ear is typically developed. His non-hearing ear has an extremely rare malformation (that excited the ENT) that doesn’t impact any other structures AND we were able to rule out a genetic syndrome that was a possibility in the bargain. So, while not medically necessary, it was a very useful test for us.

    Sorry, that was rather too long. But my point is how silly it seems to call that a placebo.

  7. BillyJoe says:

    FastBuckArtist,

    Some patients have a condition that needs no treatment (like common cold) but sometimes they insist on getting a treatment.
    Sometimes placebos are given to send the patient away.

    You managed to get in the first qualifier, but I’ve added the next two for you. ;)

  8. Janet says:

    When are reporters going to learn to check here (or with anyone reputable) before they go on about rubbish studies. I can’t tell you how many times I hear, “but it was in the NY Times…”, so I include them. If I comment on their articles, I get totally ATTACKED by the believers–usually complete with links to things like “Natural News”. Ugh.

  9. Alia says:

    Oh dear, last week I had a discussion with a philosophy student (at least that’s how he introduced himself) about the reality of placebo effect (he used singular, not plural). And he was all like “it’s all in the head, reality is subjective, so placebo is mighty”. To which I really had no answer apart from “But do you think it’s OK for patients to pay 100$ for it?” And then we parted ways.

  10. mousethatroared says:

    @Alia – Someday your philosophy student may find himself with a kidney stone and re-evaluate the “reality is in your head” idea. When I was younger I had a lot of friends who believed that we could control our health with our minds. Now that I’m older, not so many of my friends believe that, same friends, different beliefs. Reality does tend to make some impression, overtime. (on some* people).

    *that qualifier is dedicated to BillyJoe.

  11. Guy Chapman says:

    Pragmatic is SCAM-speak for “woo-friendly”. The authors of the notorious Swiss homeopathy paean use it, as do the authors of papers pleading for a less robust methodology in assessing homeopathy. It is, in context, an antonym for “robust”.

  12. pharmavixen says:

    When I was a retail pharmacist, I used to do a bit of push-back against the use of antibiotics as “placebos” in the treatment of colds. When I received what I suspected was a “get the hell out of my office”script for, say, amoxicilin for a young and healthy adult with a cold, I’d explain about the ineffectiveness of antibiotics for viral infections, and ask them to let me put the script on hold, only filling it if they took a turn for the worse (ie symptoms of a possible bacterial infection).

    A few physicians told me I was taking on a legal liability. But what about the risks of using potent pharmaceuticals as placebos, such as C. difficile and multi-drug resistant organisms?

    And even probiotics aren’t without risk. The literature has accounts of fatal fungemias resulting from the use of S. boulardii for putative C. diff prophylaxis.

  13. rork says:

    Earthman: “statistics never tell you anything is real”.
    Gavura had the word likelihood in there. He wasn’t claiming proof. You’re being too picky.

  14. geo says:

    While agreeing with the criticisms made of this paper and how it was spun, I want to add a ‘but’:

    I think that the media coverage of this paper was really helpful for encouraging a public discussion of the use of placebos. To me, it seemed like there was a strong public rejection of the dishonest paternalism that the use of pure placebo requires, even if it is efficacious (as much of the discussion seemed to assume).

    Also, within important sections of British medicine there is a belief that placebos are worthwhile treatments, even with the risk of harming patient trust. Clare Gerada (head UK GP) defended this approach on national radio (while being laughed at). It was helpful to give people another opportunity to make it clear to them how out of step with public opinion they are.

    While it may be in the interests of those making money from medical treatments to try to take credit for the wonders which result from the use of placebo, it is not something which the public want to have inflicted upon them without informed consent. It may have been the authors intent to de-stigmatise the use of placebo as treatment, but it seems that the British public is too sceptical for them.

  15. pmoran says:

    There remain sound reasons for the mainstream not to endorse the systematic use of “comfort prescribing” (all doctors will do it sometimes! ) whether placebo responses can be beneficial under some conditions or not.

    The possibility/probability that “placebos” ( more usually methods that are non-evidence-based to varying degree) produce beneficial patient responses under some conditions certainly does create ethical, practical and policy difficulties, but that is irrelevant to scientific truth. I suggest we wait until we can be more certain about the role of placebo within medicine at large, and then finalize our ethical, practical and policy stances.

    A too suffocatingly pious approach within all reaches of medicine may end up denying the public limited medical comforts that are their right, after millions of years of humanoid evolution, as well as increasing adverse drug reactions through the use of unnecessarily powerful pharmaceuticals.

    It needs to be pointed out again, that there is no point whatsoever to the use of non-EBM methods (i.e. “placebos”), at either patient choice, doctor choice, or by mutual agreement, whenever there are obviously superior, safe and effective evidence-based methods.

    So this is a peripheral, scarcely explored area of medicine. It is not yet clear what hegemony Science can exert over medicine when it lacks satisfactory answers itself.

  16. icewings27 says:

    OK, so as a patient, how do I know if I am being prescribed a placebo? Is my doctor obligated to tell me if I ask him whether he’s prescribing one?

    Or, can a doctor say he’s prescribing a real medicine but then instruct the pharmacist to replace it with a placebo instead?

    Is it possible the “meds” I’m currently taking are just really really really expensive sugar pills? How do I find out?

  17. WilliamLawrenceUtridge says:

    @icewing

    You could check the dosage, one common placebo is low-dose antidepressants, so low they aren’t expected to have main or adverse effects. There are standard dosages which you should be able to find online, and if your dose is significantly below this, it could be used as a placebo. Another option is checking the ingredients (anything made up of water and salt or sugar is by definition a placebo; active ingredients should be present on the packaging). A third is accepting what your doctor recommends (many placebos are given for self-limiting conditions and are due to patients being unwilling to wait it out). A fourth is learning about the condition from reliable sources, such as the NIH, CDC, FDA, emedicine, the Mayo Clinic and Quackwatch (the latter being primarily about disendorsements, what doesn’t work and what is quackery). Doctors aren’t infallible, second opinions can be invaluable (particularly for unusual diseases or atypical presentations), but generally for most people with common “horse” conditions (rather than zebra conditions), the banal advice you get is probably at minimum reasonable.

    From my understanding, doctors prescribe placebos to patients who demand some sort of treatment despite their doctor preferring not to give any. So it whether you are getting a placebo or not might depend on your relationship with your doctor.

  18. pmoran says:

    From my understanding, doctors prescribe placebos to patients who demand some sort of treatment despite their doctor preferring not to give any. So it whether you are getting a placebo or not might depend on your relationship with your doctor.

    Yes, doctors may occasionally use non-evidence-based treatments (the usual mainstream “placebo” — never the proverbial “sugar pill”!) with minimal or no expectation of intrinsic efficacy, but they do so mainly to avoid expected adverse consequences of not prescribing e.g. for a strongly expectant person of low intelligence. If a placebo response follows, that is a bonus, but in most instances the doctor will be relying on the tendency of most common complaints to improve quite soon whatever is done.

    Placebo use is routine within CAM, although it must be remembered that highly sophisticated considerations are often required before anyone can be reasonably sure that a treatment lacks intrinsic efficacy, especially when trying to explain the true value of otherwise intensely influential testimonials. So that which SBM regards as a placebo may be a weakly, moderately or strongly credible treatment resource for someone else.

  19. rdscptic says:

    Am I correct to think that if placebo(s) have a real physiological effect, as is increasingly claimed, then dose response curves should be detectable? i.e. more placebo should be better, in general. The stories about red coloured placebo pills being better than other colours etc abound, but is there any genuine evidence for placebo dose response? And if there is what would that mean?

  20. pmoran says:

    Am I correct to think that if placebo(s) have a real physiological effect, as is increasingly claimed, then dose response curves should be detectable?

    Placebos display a kind of dose-response curve, in that responses can be titrated up or down by manipulating patient expectations in many ways. The difficulty lies in knowing whether you are producing “real” patient benefits, or merely manipulating exploiting the tendency of subjects to provide the answers that they think researchers expect of them.

  21. geo says:

    “or merely manipulating exploiting the tendency of subjects to provide the answers that they think researchers expect of them.”

    And a desire to provide answers which they think reflect well upon them. There is some evidence that when people think the responding poorly to treatment reflects poorly upon themselves, the ‘placebo’ effect is stronger.

    Much of the attempt to present the placebo affect as a legitimate medical intervention seems either very naive, or else a dishonest attempt to take credit for the mere psychosocial management of how patients answer questionnaires. It’s nice to have people feeling happier and more relaxed, and this will lead to people feeling better, but I think that this is best understood as a social and moral matter than one which should be medicalised and used to justify doctors managing patients without informed consent.

  22. mousethatroared says:

    geo “And a desire to provide answers which they think reflect well upon them. There is some evidence that when people think the responding poorly to treatment reflects poorly upon themselves, the ‘placebo’ effect is stronger.”

    Jeez, I do this all the time. I hate telling a doctor (or PT or therapist) that something’s not working well for me. I feel like it’s my fault or they’ll think I’m just being difficult.

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