Placebos in the clinic
Authors: Stewart Justman
Journal: Journal of the Royal Society of Medicine (2013)

In 1954, it was reported in The Lancet that ‘Those who have qualms of conscience about prescribing pharmacologically useless medicines tend to use semi-placebos, such as vitamins, in the vague hope that these may do some good’.1 Except that the reasons for writing the prescriptions may not be quite so innocent, the same holds true today, decades into the era of informed consent.

According to surveys conducted in several countries, including most recently the UK,2 doctors commonly use placebos, albeit not in the ‘pure’ form of sugar pills or saline injections but treatments that appear medically valid – for example, unnecessary antibiotics, subclinical doses of medication, or indeed vitamins. While over half of the UK GPs who responded to the survey report using placebos frequently, 88% claim never to have prescribed a pure placebo. As before the era of informed consent, placebos appear to be used at the doctor’s discretion; almost invariably the same discretion dictates that they are disguised as something that might technically have some medical value. The preference for placebos with an appearance of medical legitimacy suggests that doctors are uneasy with the practice of deception even if they are not about to abandon it.

Doctors exhibit a definite preference for impure placebos in other national surveys as well – the Danish, for example. The report of the Danish survey also observes that GPs do not have time for ‘lengthy discussion’ with patients whose ailments are chronic, uncertain or both, and that ‘the main reason for use of placebo reported by the respondents was to appease a patient and not primarily to induce an effect of placebo’.3 Evidently, Danish doctors tend to use placebo not so much to promote a placebo effect as to ease the patient out the door. If so, then the placebo is actually being used more for the doctor’s sake than the patient’s.

That possibility is worth considering in connection with the UK study, inasmuch as the respondents see a mean of 123 patients per week. Given the time constraint this implies, it would make sense if placebo were sometimes prescribed to bring a consultation to an end. And yet the UK questionnaire did not ask GPs their views on using placebos for reasons of convenience. It asked whether placebos are acceptable when used for meritorious reasons – to produce a psychological or therapeutic benefit, for example.

Though doctors are well aware of the benefits of placebos, many who prescribe them seem to be thinking of themselves as well as the patient. A survey of placebo use by Canadian doctors, both psychiatrists and non-psychiatrists, found the same strong preference for impure placebos – not because they produce better results for the patient but because they are more ‘palatable’ for the doctor. ‘Ethical concerns appear less tenuous’, the authors conclude, ‘when a physician prescribes an active substance, albeit speciously’.4

A hurried doctor faced with a difficult patient (difficult in either the behavioural or medical sense) will not lack for reasons to prescribe placebo or ways of recommending it that make it sound like a legitimate therapy. Often, it seems, placebos are prescribed ‘for their psychological effect’ – a vague something that can cover any case – though other worthy-sounding principles can also be invoked. The placebo can then be recommended to the patient on the grounds that it has proven its value in clinical experience.

The line that ‘this therapy has helped many other patients’, used by 48% of the surveyed UK GPs who prescribe impure placebos, has been on the books ever since the pioneering experiments on the placebo effect by John Haygarth5 at the Bath General Hospital in 1799. Waving over his patients a worthless article then in medical vogue, he made sure to tell them of ‘the wonderful cures’ attributed to it, and recorded their dramatic reactions and reports of relief. For Haygarth the recommendation of the therapy was a kind of satirical double entendre. Scripts in trials of open placebos now refer without irony to the many patients helped by placebos,6,7 and no doubt doctors who use the same line to recommend placebos disguised as active treatments also do so without irony, for the simple reason that placebos can in some cases relieve symptoms. The fact remains, for a doctor to say of a vitamin or whatnot, ‘this therapy has helped many other patients’, is to engender the distinct belief that it is not a placebo.

Why juggle with words in this way? The UK survey suggests it is because doctors overwhelmingly disapprove of deception (82% agree that ‘placebos are not acceptable when they involve deception’), and yet also overwhelmingly wish to retain the discretion to use placebos without informing the patient. As the report of the survey notes diplomatically, ‘this raises unresolved ethical issues about how GPs approach informed consent’.

It is disturbing that the practice of using ‘semi-placebos’ to salve the professional conscience – a legacy of the days before informed consent – should still be commonplace. Informed consent came into being in tandem with the randomized clinical trial, whose participants, it was felt, had the right to know what they were getting into. As the UK and other surveys suggest, clinical practice is a different game. Here placebos are used without consent and for any number of reasons – for the patient’s good, for the doctor’s convenience, at the patient’s demand, for the sake of a psychological effect that could mean anything or nothing.

Do patients require placebos? Perhaps less than we assume. KB Thomas, himself a GP, found that ‘patients tolerate no treatment better than doctors think they will’.8 In a study of irritable bowel patients, 35% achieved adequate relief despite receiving only supportive care, an arrangement they found so satisfactory that they were ‘not overly disappointed’ to be denied the active treatment – in this case, a placebo pill.7 Care itself is the best placebo. The great risk of placebos in the clinic is that they may be used as a substitute for care.