Attitudes to and Understanding of Placebo Use : A Cross-Sectional Exploratory Study in a Malaysian Hospital

Background: This study explored doctors’ understanding of ‘placebo’, mechanisms of action, perceptions about effectiveness and concerns about use in a Malaysian teaching hospital. Methods: A survey questionnaire. Results: Respondents were 76 doctors (response rate: 55%): 52% were female, mean age was 32 years, and 61% were physicians/medical officers. Most (66.2%) never used a placebo. The main reason for use of placebos was for a possible psychological effect. Placebo use was considered unacceptable due to endangering of doctor-patient trust (59.2%) or patient deception (47.4%). Conclusion: Developing specific and professional standards and guidance on placebo use could help doctors to leverage the benefits of placebo use without endangering the doctor-patient relationship.


Introduction
Recent surveys have shown that placebo use rates vary internationally.In 2013, 12% of general practitioners in the UK reported using a pure placebo at least once in their career, with 1% reporting use weekly.Almost all general practitioners (97%) reported using an impure placebo at least once in their career (77% weekly). 1 Studies from Poland and the USA found that 79% and 45% of doctors had used placebo as a treatment, respectively. 2,30][11][12][13][14] A 2012 study found that placebo use was not acceptable for two main reasons: it threatens the doctor-patient relationship and it deceives the patient. 15The lack of a clear definition of placebo adds to the confusion. 1,16,17Since Beecher's 1955 work "The Powerful Placebo", the effect has been considered a scientific fact, 18 and our understanding of the term has evolved from considering only 'sugar pills' to acknowledging that placebo includes any condition that simulates a therapeutic environment.Placebo effects vary depending on not only whether or not a treatment is perceived to be administered, but how it is administered, and by whom. 19The potential benefit that might be realised if judicious and appropriate use of placebo were employed is large.The objective of this study was to explore doctors' understanding of the term placebo, mechanisms of action, its effectiveness, and concerns about use.

Methods
A questionnaire (in English and Malay) examining attitudes to and experiences of using placebo was developed based on existing questionnaires. 15,16Qualified hospital physicians working in a teaching hospital in Sarawak were recruited in person over a 3-month period (January-March 2015).Written consent was obtained from all respondents.Out of an estimated 360 doctors, 139 (38.6%) from 12 departments, excluding palliative care, were invited to participate.Survey questions included demographic items, items concerning the use of placebo, its effectiveness and opinions on use.Multiple responses were allowed for some items to capture as much information as possible.Respondents only responded to questions relevant to them.Respondents were also given a case in which a placebo was successful and asked to say why.Data was entered into SPSS for analysis.In the case of missing data for an item, the appropriate adjustments to the overall number of samples were made.
Of the definitions given, "placebo is an intervention that is not expected to have an effect through a known physiological method"

Short Communication
was most endorsed (49.3%), followed by "placebo is an intervention that is not considered to have any specific effect on the condition treated but with a possible unspecific effect" (38.4%).
The reasons for placebo use, what was used, when and how are presented in Table 1.Most doctors, (n=49, 66.2%) never used pla-cebo, while 20.3% did so once a year on average and 2.7% daily.There were no significant differences in placebo use by gender, age or experience.Of those who used placebo (n=25), 71.9% used it for its possible psychological treatment effect and 28.1% for constantly complaining patients or to bridge a difficult treatment situation.Almost one third (31%) used a placebo as a diagnostic tool.

Placebo Use n (%)
What motivated you to prescribe or administer a placebo?
Because of a possible psychological treatment effect 23 (71.9) For constantly complaining patients, to bridge a difficult treatment situation 9 (28.As a supplement to medication 2 (6.9) To control pain (including in the context of patient controlled analgesia) 2 (6.9) Instead of a medication in order to buy time between one dose and the next of the medication 1 (3.4)

How did you inform your patients?
It is a substance that may help and will not harm Placebo users favoured saline injection (65.6%) and vitamins (50%).Most rejected the use of antibiotics (68.6%) and ibuprofen (57.1%) as placebos.Placebo use was most frequently thought to be acceptable if used for its psychological effect (74.3%) or because it does not cause harm (34.3%).The most common reasons for placebo use being unacceptable was the possibility of endangering the trust between doctor and patient (59.2%) and deception of patient (47.4%).Respondents thought that placebo use could be permitted if research (59.5%) or excellence in the department (24.3%) supports its efficacy.More than 10% of respondents thought placebo use should be prohibited.
When prescribing placebo, 54.3% of the doctors informed the patient that "it is a substance that may help and will not harm", 37.1% informed patients that "it is a medication", and 17.1% said nothing.The majority (87.9%) of prescribing doctors observed placebo was sometimes or usually effective.For the case, most doctors (73.3%) thought that improvements in pain experienced were because the pain was psychogenic (n=55, 73.3%).

Discussion
The study provides information about doctors' perceptions of what a placebo is, its use, and attitudes towards placebo usage in a Malaysian context.Most respondents had not prescribed a placebo (66.2%).Although this is consistent with a recent Canadian study (23% used placebo), 20 it is inconsistent with other surveys reporting higher use. 1,2The reasons cited by doctors for non-use are consistent with other studies in which respondents were concerned about endangering trust or withholding information despite the prevalence of a paternalistic doctor-patient relationship in Malaysia. 6Perhaps the move towards evidence-based practice is significant as most doctors in this study felt that placebo use should only be permitted if supported by research.Most doctors reported prescribing placebo for possible psychological effects and in situations to calm patients.This may be because most doctors agreed that the mechanism of placebo is mostly psychological.
The placebo effect is influenced by a patient's positive expectation following a clinical encounter, 21 as highlighted in open/hidden studies where a placebo effect is documented but no 'placebo' is used. 22Over half of the placebo users in the current study informed their patients that the placebo was a substance 'that may help' while others referred to it as 'a medication'.Such language is likely to foster an expectation of beneficial effect in the patient.The power of expectation is very important in the therapeutic environment, yet the medical profession may underutilize this potentially effective tool as a result of poorly understanding it.
Almost a third of doctors reported using placebo as a diagnostic tool to distinguish between a genuine and imaginary symptom.It is acknowledged that use of placebos may result in an improvement in physical symptoms; hence the use of placebo in such a diagnostic capacity is, at best, ineffectual as physiological effects may occur.At worst it is dangerous as it may result in the non-treatment of genuine disorders and belies the effectiveness of placebo.
Most doctors surveyed thought the mechanism of action of placebo was psychological and felt that improvements in pain experienced as a result of placebo administration were because the pain had no organic cause and was psychogenic.These results highlight a lack of understanding of the physiological effects of placebo.While there appears to be an awareness of the power of expectation, when presented with a case of effective placebo treatment doctors appear somewhat reluctant to acknowledge the physiological power of placebo.
It has been suggested that difficulty in explaining to patients that a treatment may not help may reduce the potential placebo effect, leading doctors to use some form of deception such as not telling the patient directly that they are using a placebo. 23,24Respondents' perceptions regarding placebo effectiveness were ambivalent.While some doctors agreed that placebos are effective, most chose a neutral stance.There appears to be gaps in doctors' knowledge regarding placebos, how they work, and how they may be used, likely to limit the discussion of treatment options not specifically designed for the patient's complaint.
Limitations to this study included the small sample size and the limited setting of a single hospital (so results may not be generalizable to other hospitals in Malaysia).Small numbers of doctors were recruited from each department, hence the doctors were considered as a homogenous group and not representative of their individual departments.Further research is warranted into differing attitudes to placebo use among doctors specialising in areas such as pain management.The survey relied on doctors recalling how frequently they had used placebos in the past.Thus, we cannot determine the actual frequency of use.Strengths of this study include the use of a purpose designed questionnaire available in both English and Bahasa Malaysia.This study also contributes to the knowledge of attitudes to placebo use among healthcare professionals in Malaysia, an area which has been understudied to date.
The majority of doctors surveyed do not use placebos.A growing body of evidence on the usefulness of placebo raises the question of whether use should be recommended.This raises ethical challenges.Agreement on the range of interventions that are considered suitable to be used as placebo, and in what situations, would bring clarity to the discussion.A clear definition is needed to prevent conceptual confusion and further research should explore how doctors might harness the power of placebo without endangering the very relationship that may contribute to the effect.

Table 1 .
Placebo Use among Doctors at a Teaching Hospital in Malaysia IJMS