Ninety-seven percent of doctors have prescribed placebo treatments at least one time, according to a UK survey.

The research was published in PLOS ONE and was conducted by a team of experts at the Universities of Oxford and Southampton. The results demonstrated that 97% of clinicians have used impure placebo treatments and 12% have used pure placebos.

Treatments that are unproven are known as impure placebos. This includes antibiotics for suspected viral infections and physical examinations as well as blood tests that are not completely necessary but completed to put the patient's mind at ease.

Pure placebos are treatments that do not consist of any active ingredients, including sugar pills and saline injections.

The survey was taken online by a random sample of doctors - 783 primary care practitioners (GPs, general practitioners) in the UK. This sample was said to be representative of all physicians registered with the GMC (General Medical Council).

Results indicated that, in general, doctors who prescribed pure or impure placebos did so for comparable reasons. The physicians reported using placebos to either create psychological treatment effects - because patients asked for treatment, or to reassure patients.

Previous research suggested that placebos are activated outside the conscious mind, which explains why patients show clinical improvement even when no active ingredients are present.

"This is not about doctors deceiving patients," explained Dr Jeremy Howick, co-lead author of the study from the University of Oxford's Department of Primary Health Care Sciences. "The study shows that placebo use is widespread in the UK, and doctors clearly believe that placebos can help patients."

Similar research worldwide has also demonstrated widespread use and acceptance of placebos. A study from 2008 indicated that placebo treatments are regularly prescribed by rheumatologists and internal medicine physicians in the U.S., often without admitting the intention to the patients.

The use of placebos in the UK is not explicitly talked about or forbidden by the GMC. However, the council does suggest that physicians should always be honest with patients and explain in detail what they are prescribing.

Dr Howick said:

"The GMC is silent on placebos, which leads to ambiguity. They do state that doctors 'should not withhold information' from patients, as to do so would prevent the patient from providing informed consent. Since some ways of using placebos could involve the suggestion with the patient that the placebo is a 'real' treatment, the GMC view is often interpreted by GPs as a ban on placebos."

There were diverse results regarding ethical attitudes towards using placebos:
  • 66% of doctors said that pure placebos are ethically acceptable under particular instances
  • 84% said that impure placebos are acceptable
  • 33% said they are never acceptable
More than 90% of doctors objected to using both pure and impure placebos if it jeopardized their patient's trust and over 80% argued against use if it involved deceit.

Professor George Lewith, co-lead author of the study from the University of Southampton, concluded:

"This latest study with the University of Oxford demonstrates that doctors are generally using placebos in good faith to help patients. Other previous published studies by Southampton have clearly shown placebos can help many people and can be effective for a long time after administration."

"In my opinion the stigma attached to placebo use is irrational, and further investigation is needed to develop ethical, cost-effective placebos," Lewith added.

The study was funded by the Southampton Complementary Medical Research Trust, the University of Oxford Department of Primary Health Care Sciences, and the National Institute for Health Research.

Written by Sarah Glynn