In 2013, a survey of UK primary care physicians revealed that 97% of them had used placebos in their career, with 77% of them using placebos at least once a week. We take a look at this and what it means for both patients and doctors.

Pure vs Impure Placebos

The survey asked the doctors about two types of placebos: pure and impure placebos. Pure placebos are what we traditionally think of when we talk about placebos. They’re sugar pills, saline injections or other interventions without any direct pharmacologically active ingredients for the condition being treated. On the other hand, impure placebos are interventions which are clearly effective for the treatment of certain conditions, but they are prescribed for other conditions where their effectiveness is not known. We have listed examples of impure placebos from the study, below:

  • Positive suggestions (52% of respondents)
  • Nutritional supplements
  • Probiotics for diarrhoea
  • Peppermint pills for pharyngitis
  • Antibiotics for suspected viral infections inc. colds (25% of respondents)
  • Sub-clinical doses of effective therapies
  • Off-label uses of a potentially effective therapy
  • Complementary and alternative medicine whose effectiveness is not evidence-based
  • Conventional medicine whose effectiveness is not evidence-based (26% of respondents)
  • Non-essential physical examination (54% of respondents)
  • Non-essential technical examinations i.e. blood tests, x-rays etc. (31% of respondents)

Why use placebos

The study found that the reasons for prescribing pure and impure placebos were similar, but did vary across the groups. The following table outlines the reasons for prescribing a placebo and the percentage of doctors who admitted to using pure vs impure placebos for these reasons:

ReasonPure Placebos Impure Placebos
To induce possible psychological treatment effects55%50%
To calm patients32%32%
Because a patient requested a therapy32%45%
To treat non-specific complaints31%35%

This shows that GPs will most often prescribe placebos to induce possible psychological treatment effects i.e. to make the patient feel better, even if it is not making any physical improvements. Interestingly, impure placebos were much more likely to be prescribed because a patient requested the therapy. This may demonstrate how doctors sometimes feel the need to humour a patient and to allow them to have a therapy they request even if there is no evidence base behind it. Whilst the survey did not cover this, it may be that the internet offers a means for patients to become better informed about their health, but not to identify which treatments would be most suitable, therefore it could be considered part of the doctor’s role to guide patients towards the right decisions when it comes to treatment.

The prevalence of placebos in primary care

The study involved a survey of UK general practitioners (primary care physicians). Only 46% of them responded, but demographic data does suggest that these results could be generalised to reflect UK-wide practices.

The study found that 12% of GPs had used pure placebos, whilst 97% had used impure placebos at least once in their career.

To assess whether placebo usage was just in one-off situations, they asked how often physicians used placebos finding that 1% of GPs used pure placebos at least once a week and 77% used impure placebos at least once a week.

What about the rest of the world?

Similar surveys have been conducted in other countries around the world, finding that 17-80% of doctors prescribe placebos. The table below outlines some of the results of placebo use by country, indicating the year in which the study was published. The results are incomplete, but we provide details of impure and pure placebo use, as well as total placebo use, where these values are available.

CountryYearImpure Placebo Use Pure Placebo Use Total Placebo Use

These figures demonstrate that placebo use does vary across countries, but even at its lowest, placebos are still in common use. It is interesting to note that the lowest use of placebos were found in the USA and Switzerland – both countries with completely privatised healthcare systems. It may be that in a private system, doctors are more accountable to patients and insurance companies, so it could be more problematic to issue placebos in these environments.

The Ethics

With placebo use being so prevalent in primary care, it is clear that we rapidly need more research into the ethics surrounding this area. Most of the doctors surveyed believe that it is ethical to use placebos in some circumstances. Specifically, 66% stated that pure placebos could be used ethically and 84% stated that impure placebos could be ethical in some situations.

One of the core principles of modern medical ethics is informed consent. Doctors are no longer supposed to be the paternal figures they were previously, instead now patients should be involved in making decisions about their health and treatment. The deceptive use of placebos removes informed consent from the patient and could potentially damage the doctor-patient relationship by breaking down trust. In relation to this, the survey found that approximately 82% of doctors felt that placebos (pure or impure) were not acceptable when they involve deception. 90.2% of doctors felt that pure placebos were not acceptable when they endanger trust between doctors and patients, 93.6% felt this to be the case for impure placebos. These were the highest scoring responses of the ethical questions in the survey, demonstrating the importance of placebos being used openly if they are to be used in primary care. Interestingly, when GPs do prescribe placebos, more than half of them have informed their patients that the intervention has helped other patients, without specifically telling them that they were prescribing a placebo. This technique may be an ethical compromise, allowing the patients to know a genuine reason for the treatment, but not fully disclosing the nature of that intervention. Since these findings, much research has explored the idea of open-label placebos (placebos that the patient and doctor know are placebos). So far, the results of these studies have proven to be very promising, with several patients responding to open-label placebo treatment, suggesting a viable and ethical way for placebos to be integrated into primary care.

If placebos are to be integrated into primary care, the risk vs benefit also needs to be established. Several of the ethical questions related to this topic. For example 49.7% believe that pure placebos can be used when all other treatment options have been exhausted, this figure increased to 66.5% for impure placebos. Similarly, placebos were thought to be unacceptable to use if they have possible adverse effects upon the patient (41.6% for pure placebos and 55.8% for impure placebos). Perhaps surprisingly, given the previous responses, the efficacy of placebos did not seem to matter quite so much for using impure placebos as it did for pure placebos. The results show that only 35% of doctors believe it would be inappropriate to use impure placebos due to inefficacy, but 52.8% believe it would be unethical to use pure placebos in this way. This is an interesting dichotomy, but it does suggest that impure placebos may be perceived as more honest or ethical than pure placebos.

The remaining ethical questions on the survey relate to reasons why placebos would be prescribed. Given that possible psychological treatment effects were the most common reason placebos were prescribed, it is not surprising that most doctors believe that it is acceptable to use placebos in this way. 52.8% of doctors believed that pure placebos could be used acceptably for psychological effects and 58.3% believed that impure placebos could be acceptably used for that purpose. In addition, 32-45% of doctors admitted to using placebos because a patient had requested a therapy. The survey asked if it is acceptable to use placebos if a patient wants or expects this therapy. 47.2% of doctors said this would be ethical for pure placebos and 46.7% for impure placebos. Given how important informed consent and shared-decision making is in modern medical practice, this statistic may be lower than expected. But it does suggest that some doctors feel they have a professional obligation to steer patients away from placebo treatments. Despite this, there were strongly positive results for doctors making decisions regarding the use of placebos based on their own clinical experience. 60.7% of doctors stated that it would be acceptable to use pure placebos when clinical experience has shown benefits, increasing to 79% for impure placebos. Presumably, the increased figure for impure placebos may be related to a possibility of the treatment having some unknown or unconfirmed benefits due to the active qualities of the treatment.

These ethical perspectives show much about how placebos may one day be integrated into primary care, but they also demonstrate the obstacles that could hinder this process. Future research into the placebo effect in primary care should take these ethical factors into consideration to encourage translation from research to the clinical realm.

What to take away:

  • Not all placebos are sugar pills or saline injections, but they can include a wide array of different impure placebo techniques.
  • Whilst the number of doctors who have used pure placebos is limited, a vast number of doctors around the world do issue impure placebos as part of their clinical practice.
  • There are clear ethical issues surrounding the use of placebos in primary care which must be addressed. A survey of patient perceptions of the placebo effect would help to inform the debate in this area. Given the current prevalence of placebo-use by primary care physicians, it is imperative to open this discussion and to reach a medical consensus on the ethical use of placebos in this context.
  • If you’d like to learn more about the clinical guidelines relating to placebo use, please visit our page: A doctor’s guide to placebos.

Taking the debate further

We’d love to hear from doctors and patients about their perspectives on the ethics of the placebo effect. Please feel free to get in touch and share your thoughts with us. Alternatively, why not comment on this article. We hope to conduct a series of surveys and interviews of patients and primary care physicians in the future to inform the debate in this area.

Where to find the study

One thought on “The secret prescription – Do doctors use placebos?

  1. I would be a bit annoyed if I was prescribed a placebo without my knowledge as I would think I had not been taken seriously. But if I was told that the ‘medicine’ might initiate a response in my immune system, I would be happy to try it. I do not need to be informed about the ‘active’ ingredients, just that the medicine works for some people.There should be more research into placebos generally and how the immune system works. It would be beneficial if the public were better informed about it. Doctors are under many pressures from patients demanding certain treatments, and also pressure from other directions about saving money for the NHS and not spending too much time with patients. Many patients may feel entitled to come away from the appointment with a prescription but the over prescribing of antibiotics may in part be due to laziness of doctors who do not explain why they are not appropriate for viral infections. There is, sometimes, a feeling that the doctor just wants to get through his appointments as quickly as possible.

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