• Placebos

    Placebos receive little attention in the health policy space. I’m not sure if they are understudied by researchers, but it seems so. Are they underused or overused? How much do we pay for them? What are the benefits and harms? What are the ethical considerations?

    The recent PLOS ONE paper by Jeremy Howick and colleagues is a good place to start.

    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. The analysis indicates potential gender differences in the frequency of placebo prescriptions. […]

    The survey instrument was derived from previously published investigations and enables our data to be easily compared with other international studies. A 2009 systematic review of 22 surveys of placebo use in general practice in 12 countries found 17% to 80% of practitioners had used ‘pure’ placebos at least once in their career and between 54% and 57% had used impure placebos at least once in their career. The latest survey of placebo use was published after the systematic review and found 45% of German GPs had used pure placebos and 76% had used impure placebos in the last year. Hence the results of our UK survey are internationally consistent.

    A “pure placebo” has no active ingredient, like sugar pills or saline injections. An “impure placebo” has an active ingredient appropriate for some conditions but used in circumstances for which their efficacy is unknown or known to be of little to know value, like antibiotics for viral infections.

    What if comparative effectiveness or cost effectiveness analysis led to a reduction in use of impure placebos or an increase in the use of pure placebos?


    • There is also a Nocibo effect. Cost of studying nocibo and placebo in the policy space is not worth the expense. We waste more money on homeopathic meds and vitamins and non-beneficial alternative therapies.


    • This is a horribly flawed study that doesn’t even come close to demonstrating what the sensationlist headline and title claims to. While not sufficient alone to impugn the study, the fact that both authors have funding and do work for so-called CAM groups and one is a credulous writer on homeopathy is important.

      The real reason that it is horribly flawed is that they have (seemingly) intentionally set up a definition of placebo that is so broad and vague as to be utterly meaningless. First off, only 12% of physician were noted to have ever used a pure placebo, even just once in their entire careers. Of those, only 1.5% used pure placebo “occasionally” which is defined as “approximately once or month or at least once in the last year.” That really doesn’t strike me as strong support of the notion that physicians use pure placebos very much at all.

      But the real issue is in the impure placebos. By the definitions the authors used I am genuinely surprised that only 97% of physicians were found to use placebo. They define “impure placebo” as including:

      “Positive suggestions”
      “Off-label uses of potentially effective therapies”
      “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)”

      By that definition I would argue that it is impossible to practice medicine without the use of “placebo” and I really wonder about those 3% of surveyed physicians who have never given their patients “positive suggestions.” I personally can’t imagine ending a consultation without at least one positive suggestion.

      From my perspective this is not evidence for further exploration of placebo medicine in the legitimate practice of medicine, but an attempt at a propaganda piece to demonstrate the false “power of placebo” now that alternative medicine and “integrative” medicine proponents are forced to acknowledge that CAM is nothing more than modern day snake oil in the form of placebo medicine.

      For excellent discussions by pharmacist Scott Gavura:


      And neurologist Steven Novella:


      • An excellent point. This study does appear to be fundamentally flawed in the basic definitions used. Really seems to say nothing about placebo by any accepted understanding of the term.

    • I have another thought. First off, since the Flexner report period, most physicians are somewhat fearful that they might be seen as unscientific, and even though the placebo effect IS scientific, I don’t think you can rely on what anyone SAYS about what they do. Revealed preferences, watch what they do and read their minds (I know, rather difficult). People’s attitudes and perceptions about information, and what they view as explicit vs. tacit information (and what they perceive, which may be different yet again) affect how they behave and their explanations for their decisions.

      The impure and pure placebo effects also are not separable, it may not be possible to know where the effect is coming from. The real problem, as it is in much of diagnostic and treatment medicine, is inconsistent use of and understanding of uncertainty in the problem. We know relatively little with certainty. But of course, we have to act, so we do. And admintting our uncertainty may break the impure AND pure placebo effects, so are we honest about how much we don’t know?