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| Journal of the New Zealand Medical Association,
05-June-2009, Vol 122 No 1296
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Patients’ attitudes to the use of placebos:
results from a New Zealand survey
Guo-Feng Chen, Malcolm H Johnson
The administration of placebo as an intervention in clinical
practice has been well-documented. Studies have shown that many physicians do
not hesitate to administer a placebo intervention in various clinical
situations.1–6 In a Danish study of 545
clinicians, as many as 86% reported use of placebo interventions at least once,
and 48% to have used placebo interventions more than ten times within a year
4, while 60% of a group of 89 clinicians in
Israel used placebos and over 30% did so more than once a
month.5 In a very recent study of a United
States sample of internists and rheumatologists about half of the 679
respondents acknowledged prescribing placebo
treatment.6
Although apparently quite widely occurring, the use of
placebo interventions in clinical practice is generally regarded as unethical
because it fails to include informed consent, and often involves deceit of a
patient.7 Unfortunately, we have little
information about the attitudes of patients to placebo treatment or their
understanding of the construct. The limited literature suggests that along with
health professionals, patients are not well informed and generally lack
awareness of the placebo effect.3,8,9
In one study surveying 300 rheumatology inpatients about
their beliefs regarding the placebo effect in the treatment of chronic pain, the
authors found that patients had little knowledge of the placebo effect and
tended to underestimate it, and concluded that more attention should be directed
to better understand patients’ views of the placebo
construct.8
As evidence grows for a biologically active basis for
placebo action mediated by expectation and conditioning processes in conditions
such as pain,10–13 Parkinson’s
disease,14–17 and
depression,18–21; along with evidence
that much of the efficacy of some “real” treatments is attributable
to placebo effects,22–24 arguments for
the use of placebo in clinical practice are likely to
grow.10,25–27 However, even if health
professionals are ready to “exploit” placebo power, the question of
whether placebo administration is acceptable to patients and the impact that
placebo administration might have on the healing encounter is unknown.
Without sound knowledge of how patients generally view the
use of placebos, no one can answer this question with certainty. Clearly, we
need additional information to predict the likely impact of the use of placebos
on patients’ perceptions of their medical experience. Therefore, shifting
the research focus to examine patients’ attitudes to placebo use will
benefit the existing literature.
At this point in time, the one circumstance in which placebo
can be ethically administered is in the context of a clinical trial in which the
participant is informed about the possibility of receiving a placebo rather than
the procedure or pharmaceutical being
investigated.10,28,29 Although there has been
much recent discussion regarding the ethics of placebo administration in this
circumstance,29–31 there is little
systematic evidence regarding consumer views of placebo use, other than one
qualitative study of Japanese laypersons that found the use of placebo was
related to more negative attitudes toward participating in medical
research.32
We examined whether patients were amenable to the use of
placebo in various clinical situations, their willingness to participate in a
PCT including their reasons for or against participation, and their beliefs
about the placebo effect.
MethodsQuestionnaire—We developed a
questionnaire on beliefs about placebo and attitudes to the use of placebos in
clinical practice and in clinical research. We sought information on basic
demographics, willingness to participate in a PCT, attitudes to the use of
placebos, and beliefs about the placebo effect. Placebo was briefly defined in
the questionnaire as: ‘an inactive treatment such as a sugar pill that
looks like the real pill and is given in the same way as a real pill’.
Additionally, we asked whether patients had chronic or acute conditions.
Attitudes to the use of placebo were investigated using
the APTS, a 10-item questionnaire adapted from an earlier study examining
doctors’ attitudes to the deliberate use of placebo as
treatment.1 However, the earlier study only
examined the APTS as individual items. For the present study we wished to
accumulate an overall score.
For each of the ten items, participants are asked to
express what they believe is the right action for a medical practitioner to
take. Prior to the main statistical analyses, the factor structure of the APTS
was examined using principal components analysis. Initial results using varimax
rotation suggested a two factor solution but with five items loading above .35
on both factors and eigenvalues of 3.27 and 0.34 for the factors.
As the scree plot and eigenvalues suggested a single
factor, an oblique rotation (direct oblimin) was used. From this analysis, it
was concluded that a single factor solution with nine items that had an
eigenvalue of 3.81 and explained 42 % of the total variance was appropriate.
Factor loadings are shown in Table 2. Item 1 had an
extremely low factor loading compared to the other nine items and was not
included when the total score was calculated.
The Cronbach’s alpha for the APTS is .822. The
individual scores are summed to give an overall score ranging from 9 to 45. A
higher score would mean that the participant is more amenable to the use of
placebos.
Recruitment—Consecutive general
practice patients waiting to see their doctors were recruited from two clinics
with different socio-economic populations in the Auckland area of New Zealand.
The inclusion criteria for participation were; (1) patients had to be over 18
years old; (2) patients were required to be literate in English. Of the
approximately 440 patients approached who consented to participate, 211 returned
completed questionnaires, a response rate of 48%.
Statistical methods—Statistical
analysis was carried out using version 12 of the Statistical Package for Social
Science (SPSS). The significance level was set at .05 for all statistical tests.
P-values less than 0.05 and 0.01 were reported. To compare group differences in
means of the APTS, independent samples t tests were used. The associations
between continuous variables of interest were determined using Pearson
correlation coefficients. Factor analysis was used to examine the psychometric
properties of the APTS.
ResultsTable 1 shows the basic demographics of the entire sample.
The uneven gender ratio probably reflects the general pattern that females visit
their physicians for advice and treatment more frequently than
males.33,34 The age of the sample no doubt
results from the impact of age on health. The number reporting tertiary level
education (47%) is slightly higher than the 40% of adults that reported having
tertiary qualifications in the 2006 New Zealand
census,35 perhaps because some people will
engage in tertiary education without receiving a qualification.
Frequency—The results of the
responses to the individual items on the APTS for the entire sample, expressed
as percentages are shown in Table 2 while Table 3 presents the means and
standard deviations of the APTS. Items 1, 3 and 9 were found to be the most
appropriate uses of placebo. In item 1, 27% would definitely consider use in
this way, while over 78% would consider use in this way on at least rare
occasions. In item 9, over 32% would definitely consider use in this way, while
over 68% would consider use in this way on at least rare occasions.
In item 3, over 53% would consider use in this way on at
least rare occasions. Items 4, 6 and 10 were found to be the most inappropriate
uses of placebo. In item 4, over 72% would definitely not consider use in this
way, while 82% would either consider it definitely not appropriate or only as a
last option. In item 6, over 36% would definitely not consider use in this way,
while over 64% would either consider it completely inappropriate or only as a
last option. Finally, in item 10, over 48% would definitely not consider use in
this way, while over 71% would either consider it completely inappropriate or
only as a last option.
Examination of individual scoring patterns for the APTS
showed only one participant considered all uses of placebo were definitely not
appropriate and one considered that all uses were definitely appropriate. While
there was a tendency for participants to be either more or less agreeable to the
various uses of placebo, 117 participants discriminated the various possible
uses and responded definitely appropriate to at least one use and definitely not
appropriate to another.
Table 3. Means and standard deviations of the
APTS of the whole sample, by gender and by medical condition
Comparisons of group differences were made for gender and
medical conditions. The mean and standard deviation of the APTS score for the
entire sample was 22.34 and 7.93 respectively. Male participants (M=24.31,
SD=8.37) had significantly higher mean APTS scores than female participants
(M=21.75, SD=7.72), t (209) =1.99, p<.05. However, chronic and acute
patients did not significantly differ on the APTS scores.
Table 4 presents the correlations between the variables
total APTS scores, age, and education. Age correlated positively with total APTS
scores (r=0.14, p<0.05), and level of education correlated negatively with
total APTS scores (r=-0.29, p<0.01).
Table 4 Intercorrelations between the APTS and
demographic variables
Willingness to participate in a placebo-controlled
trial—Table 5 shows the responses of willingness to participate
in a hypothetical PCT. Overall, 59% of the entire sample would be willing to
participate in a PCT. The reasons most often given were:
The reasons
most often given by unwilling participants were:
Eighty
seven percent of the patients stated that they would not lose trust in their
physician if asked to participate in a PCT. No significant findings were found
for the influence of sociodemographic variables - gender, medical condition,
age, or education on the decision to participate or not in a clinical
trial.
Patients’ beliefs about the placebo
effect—Table 6 shows the responses to patients’ beliefs
about the placebo effect. Over 65% were unsure that placebos would work in
general. More interestingly, less than 5% either agreed completely or agreed for
the most part that placebos, in general can cause bad side effects. Less than
17% either agreed completely or agreed for the most part that a placebo can
provide complete pain relief. Over 21% agreed completely or agreed for the most
part that the effect of a placebo can last as long as that of the real
treatment. Less than 9% either disagreed completely or disagreed for the most
part that the effectiveness of a placebo was dependent on the personality of the
patient. Over 5% either agreed completely or agreed for the most part that two
placebos can be more effective than one.
Table 5. Willingness to participate in a
placebo-controlled trial for the entire sample
 Table 6. Patients’ beliefs about the
placebo effect
DiscussionPrincipal findings—The present study
is the first to utilize the individual items in a scale, and is the first to be
used with a patient population. The high reliability coefficient of 0.82 for the
APTS suggests that it was appropriate to use with a patient population. The mean
score of 22.34 (out of 45) for the entire sample provided evidence that overall,
patients were quite conservative about the use of placebos. However, examining
the individual items on the APTS (Table 2), it was clear that patients in the
present study were amenable to the deliberate use of placebo manipulations in
some situations although their lack of knowledge regarding the finer details of
the placebo effect provides a context for this finding.
Interestingly, males had a significantly higher overall
score than females (24.3 and 21.8), suggesting that male patients in general are
more likely to view the use of deliberate placebo manipulations as more
appropriate than female patients.
Two interesting but not unexpected patterns emerged from
examining the individual items on the APTS. Firstly, placebo use was considered
more appropriate when it was used for the benefit of the patient, was at their
request, or when there seemed to be no available alternate treatment. Secondly,
placebo use was considered inappropriate when it was used for the benefit(s) of
the physician or in situations where it seemed use was dangerous and without
possible benefits to the patient.
Overall, on four of the ten items, over 50% of the
participants surveyed would consider the use of placebo on at least rare
occasions, and on three other items over 40% would consider the use of placebo
on at least rare occasions. These results clearly show that many patients are
amenable to the use of deliberate administration of placebo in some
circumstances.
Even though the use of a placebo as a diagnostic tool is
dubious, over 51% of the patients surveyed would consider use in this way on at
least rare occasions as revealed by responses to item 2. This indicates that
patients are unaware that use of placebo as a diagnostic tool is ineffective and
inappropriate. The percentage of patients that responded definitely not
appropriate to the items ranged from 16.2% to 72.0%.
The percentage of patients that responded definitely
appropriate to the items ranged from 4.3% to 32.5%, which may reflect a degree
of conservatism on the issue of placebo use.
Theoretical framework—The concept of
paternalism is defined as an action taken by one person in what he takes to be
the best interest of another without the explicit consent of the person to be
benefited.9 The results from the present study
indicated that in many situations patients appear to be paternalistic in their
attitudes to the deliberate use of placebo manipulations. Interestingly, it has
been argued that acceptance of a placebo by a physician can encourage other
kinds of deception in medicine.36
This might suggest that patients who are accepting of the
use of placebos are likely to be accepting of other kinds of deception in
medicine. However, the primary question in how patients react to complex
situations such as placebo interventions is whether the primary expectation of
the patient is “First, tell me the truth” or “First make me
feel better.”9
One explanation for why so many patients in the present
study considered the use of placebos to be appropriate could be because
patients’ judgments are based on the primary expectation of making the
patient feel better. The majority of the placebo manipulations on the APTS are
suggested with the benefits of the patient in mind. Thus, it is conceivable that
a large proportion of the patients surveyed believed that placebo manipulations
would in some way benefit the patients involved.
Willingness to participate in a
PCT—The present study found that 59% of the patients surveyed
were willing to participate in a hypothetical PCT. This finding is considerably
higher than that of the 44% found in the sample of schizophrenia
patients.37
In our study, one cannot preclude the possibility that
approving participation may represent an altruistic, socially desirable
response, particularly as participants were not actually asked to participate.
This is reflected by the fact that all of the participants who reported
preparedness to participate would do so to support the development of new
treatments/help other patients. This is interesting, because the concepts of
contributing to medical knowledge and having the opportunity to help other
patients in research trials are typically underemphasised in participant
information and consent forms.38
The present finding would strongly suggest that covering
these areas more fully in consent explanations may facilitate patient
involvement in PCTs. Of equal importance, more explicit focus on the altruistic
aspects of participation should clarify the meaning and purpose of these trials
and may guide patients to a more informed level of understanding from which
their decisions can be made. For example, it would be inappropriate for
researchers to emphasize the benefits of the trial without also acknowledging
the personal risks involved for each patient.
It is encouraging to note that only 9% would participate to
please their physicians, and only 18% would participate to talk to their
physicians more often. These results indicate to some extent that patients are
quite independent in their decision making regarding participation in a PCT. The
fact that only 13.5% of the patients surveyed would lose trust in their
physician if asked to take part in a PCT further suggests that patients are
generally open to discussions about such trials.
Beliefs about the placebo effect—The
finding that only 5% believed that placebos can cause bad side effects is
significant because this would suggest that up to 95% of those patients involved
in placebo trials that experience a marked improvement or side effects may
conclude that they are receiving the active drug. Interestingly, only 8%
disagreed that the effectiveness of a placebo was dependent on the personality
of the patient. Such beliefs may be perpetuated by the general view that
placebos would only cure illnesses that are all-in-the mind. These findings are
consistent with a previous study examining rheumatology inpatients’
beliefs about the placebo effect.8 Overall, the
results clearly indicate that patients are not well informed and have
misconceptions about the placebo effect.
Strengths and weaknesses of study—The
findings from the present study are limited by a number of issues. Firstly, the
study is geographically restricted, as only two health clinics were sampled in
the Auckland region albeit from different socio-economic areas. Secondly, there
may be bias in those that chose to complete the questionnaire.
Finally, caution is warranted in interpreting these
findings, as a problem inherent in all research using open questionnaires is
that the response possibilities are specified and that the respondents may be
biased to give socially acceptable answers. For example, in this study we asked
patients to respond to a theoretical situation. Were they offered a placebo in a
genuine clinical situation their response might of course be quite different and
future research might fruitfully take up the challenge of such an
investigation.
Implications—Many studies have shown
that placebo manipulations are widely utilized in medical practice. However,
some researchers have advocated banning the use of placebos because of the
deception involved in administration and the possible harm to the
physician-patient relationship.10,39
The present study reveals that many patients are amenable to
the use of placebo manipulations particularly when they are used at the
patient’s request, for the benefit of the patient or when there is no
other available alternate treatment. Obviously, from a patient’s point of
view, there must be occasions when an appropriate prescribed placebo will be
less harmful and perhaps more beneficial than a complex and incompletely
understood drug. For example, when the physician is dealing with patients with a
history of substance abuse or when patients have to be withdrawn from certain
addictive drugs.
In such cases, giving placebo without obtaining informed
consent, may well contribute to the patient’s well-being, and in addition
would not imply that the physician is withholding a possibly beneficial medical
treatment. However, discovery of placebo use could still contribute to loss of
confidence by the patient in the medical practice and the widespread use of
placebos in clinical practice without informed consent could undermine the
contribution of expectation to therapeutic outcome not only for placebos but
also for “real” therapeutics.
The findings from the present study strongly support the
need to examine important issues of deception, informed consent and
appropriateness of placebo use in research and in clinical practice. Programs to
educate patients should be developed to overcome the current misperception and
misunderstanding of placebos. Similar surveys in other geographical areas may
reveal cross-cultural differences, while similar studies on specific patient
populations may also reveal interesting differences or similarities.
Competing interests: None known.
Author information: Guo-Feng Chen, Masters
Student, Department of Psychological Medicine; Malcolm H Johnson, Senior
Lecturer in Health Psychology, Department of Psychological Medicine; Faculty of
Medical and Health Sciences, University of Auckland
Correspondence: Malcolm H Johnson,
Department of Psychological Medicine, Faculty of Medical and Health Sciences,
University of Auckland, Private Bag 92019, Auckland, New Zealand. Email: mh.johnson@auckland.ac.nz
References:
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