A survey of UK doctors found that 97% have prescribed placebo treatments to patients at least once in their career.
Researchers at the Universities of Oxford and Southampton discovered that 97% of doctors have used 'impure' placebo treatments, while 12% have used 'pure' placebos.
'Impure' placebos are treatments that are unproven, such as antibiotics for suspected viral infections, or more commonly non-essential physical examinations and blood tests performed to reassure patients. 'Pure' placebos are treatments such as sugar pills or saline injections which contain no active ingredients.
A random sample of doctors was surveyed online, and returned 783 responses. This sample was found to be representative of all doctors registered with the General Medical Council (GMC). The results are published in the open-access journal PLOS ONE.
The survey showed that doctors prescribing both pure and impure placebos reported doing so for broadly similar reasons. Placebos were mainly given to either induce psychological treatment effects, because patients requested treatment, or to reassure patients.
'This is not about doctors deceiving patients,' says 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.'
This widespread use and acceptance of placebos is consistent with similar studies worldwide.
In the UK, the GMC does not explicitly discuss or prohibit the use of placebos in the treatment of patients, other than mentioning placebos in a footnote of their research guidance. But the council's guidance does advise that doctors should always be open with patients, explain what they are prescribing and to answer a patient's questions honestly and fully.
'The GMC is silent on placebos, which leads to ambiguity,' believes Dr Howick. '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.'
Ethical attitudes towards placebo usage varied among the UK doctors surveyed, with 66% saying that pure placebos are ethically acceptable under certain circumstances and 33% saying they are never acceptable. Impure placebos were more widely accepted, with 84% of doctors deeming them 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.
'This latest study with the University of Oxford demonstrates that doctors are generally using placebos in good faith to help patients,' says Professor George Lewith, co-lead author of the study from the University of Southampton. 'Other previous published studies by Southampton have clearly shown placebos can help many people and can be effective for a long time after administration.'
Professor Lewith adds: 'In my opinion the stigma attached to placebo use is irrational, and further investigation is needed to develop ethical, cost-effective placebos.'
The research was funded by the National Institute for Health Research, the University of Oxford Department of Primary Health Care Sciences and The Southampton Complementary Medical Research Trust.