This site is intended for health professionals only

Three quarters of GPs ‘administer placebos once a week’

More than three quarters of GPs prescribe a placebo treatment or use some form of placebo test at least once a week, despite it being widely regarded as against GMC guidance, according to a new study.

In a survey published in the open-access journal PLOS ONE, 77% admitted to using ‘impure’ placebos such as non-essential physical examinations or blood tests performed to reassure patients, or prescribing antibiotics for suspected viral infections or probiotics for diarrhoea, at least once a week. Some 97%admitted to using an ‘impure’ placebo at least once in their career.

12% of GPs admitted to having using ‘pure’ placebos such as sugar pulls or saline injections which contain no active ingredients, while 1% said they used such placebos at least once a week.

The GMC does not give specific advice on placebos, but does warn that doctors ‘should not withhold information’ from patients, and many GPs perceive using placebos to be against this guidance.

Researchers from Oxford and Southampton Universities surveyed a random sample of GPs online, and received 783 responses. The sample was found to be representative of all doctors registered with the GMC.

The survey also asked GPs for their reasons for prescribing placebos and their attitudes towards them.

GPs reported similar reasons for prescribing both ‘pure’ and ‘impure’ placebos; to induce possible psychological treatment effects, to calm patients, because their patient requested a therapy, and to treat non-specific complaints.

Ethical attitudes towards placebo usage varied among doctors, with 66% saying that pure placebos were ethically acceptable under certain circumstances and 33% saying they were never acceptable. However 84% of GPs deemed impure placebos acceptable.

For both pure and impure placebos, over 90% of doctors objected to their use where it endangered patient-doctor trust and over 80% were against using them if it involved deception.

The amount of information given to patients also varied. More than half (53%) of GPs who prescribed pure placebos told patients that ‘this therapy has helped many other patients,’ a quarter (25%) told patients that the treatment promoted self-healing and almost a tenth (9%) told the patient the treatment was a placebo, with the results fairly similar for impure placebos.

Professor George Lewith, co-lead author of the study from the University of Southampton, said that the stigma attached to placebo use was ‘irrational’ and it should be investigated as a cost-effective treatment.

He said: ‘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. 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.’

Dr Jeremy Howick, co-lead author of the study from the University of Oxford, said the GMC’s silence on placebos was leading to confusion over their use.

He 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.’

Niall Dickson, chief executive of the GMC, said: ‘Patients must be able to trust their doctors. We know from having spoken to patients that they want doctors to be honest and open with them and give them the information they need to make decisions about their health and healthcare.’

Impure placebos

·         Positive suggestions

·         Nutritional supplements for conditions unlikely to benefit from this therapy (such as vitamin C for cancer)

·         Probiotics for diarrhoea

·         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)

Pure placebos

·         Sugar pills (which are available commercially)

·         Saline injections without direct pharmacologically active ingredients for the condition being treated