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Katie Featherstone Department
of Social Medicine, University of Bristol, Bristol BS8 2PR
Correspondence to: Dr Donovan jenny.donovan{at}bris.ac.uk
Objectives To explore trial participants'
understandings of randomisation.
The randomised controlled trial is the widely acknowledged design
of choice for evaluating medical and surgical
treatments.
1 2
Though textbooks and reports of trials in
journals focus on issues concerned with design, methods, and
results,1-3 the patient's perspective is relatively
neglected. Published research has mostly used questionnaires to examine
attitudes towards participation in order to improve accrual.
Satisfaction with trial participation is reported by 90-97% of
patients.4-6 Those (75-93% of respondents) who said they
would participate in future trials cited altruism5-7 and
personal benefit
5 6 8 9
as reasons. Difficulties with
travelling and time taken were the only major
criticisms.
4 6 8
Studies of the public or outpatients
indicate that 50-75% would probably participate, with 10-20%
definitely refusing.
8 10 11-14
Interpretation of these
studies is difficult because of their reliance on general issues or
hypothetical trials, which do not have direct relevance to actual
participation in real trials. Recent research has explored how
patients' preferences might be incorporated within trials because of
their potential influence on outcome.15-19
Two studies have used qualitative research methods to explore more
detailed perceptions of methods and terms employed by trials. Roberson
et al found that although respondents were familiar with the term
"experimental study," two thirds had not heard the term "clinical
trial."20 Snowdon et al, using in-depth interviews with
parents of critically ill babies, found that the nature of the trial
was often poorly understood and that there were particular problems
with the concept of random allocation, and considerable confusion and
anger relating to parents' desire for the most suitable treatment for
their child.21
The existing research record has tended to focus on hypothetical
questions, often in trials of rare conditions, or in Snowdon et al's
case, parents of critically ill babies.21 The study reported here uses qualitative research methods to elicit the perspectives of "ordinary" middle aged and elderly men who require elective treatment for a common condition and who have themselves agreed to participate in a pragmatic randomised controlled trial. This
paper focuses on the ways in which they make sense of the concept that
lies at the heart of the randomised controlled trial: random
allocation.
The study involved patients eligible for the CLasP study. This
comprises three linked pragmatic randomised controlled trials to
evaluate the effectiveness of a new technology (laser therapy) compared
with standard surgery (transurethral resection of the prostate Sampling in qualitative research uses non-probability methods,
including "purposeful" sampling, in which individuals with particular characteristics are deliberately and systematically selected
to explore emerging analytical themes. In this study, 20 participants
were interviewed; they came from each of the major clinical centres (11 from A, nine from B), different treatment arms (five conservative
management, eight laser therapy, seven TURP), and at different time
points (seven within 3 months and five within 5 months of
randomisation, and eight after receiving treatment). Men who chose not
to participate were also interviewed (these data will be reported
elsewhere).
Data were collected by in-depth interviews carried out by KF using a
semistructured checklist of topics,23-25 covering the same basic issues, including initial symptoms; recall, understanding, and experience of recruitment; feelings about participation;
experiences of treatment; and outcome. The aim was to encourage the men
to relate stories about their experiences and to explore their
understandings of what had happened. Interviews were conducted in the
men's homes and recorded on audio tape; they lasted from half an hour
to one and a half hours. Each interview was transcribed by KF verbatim, including descriptions of non-verbal factors where appropriate. Analysis of the data proceeded by detailed scrutiny of the transcripts to identify common themes, which were coded; these coded segments of
text were included in separate word processing files.26
These files were expanded with new transcripts and refined, focused, or
altered as new themes emerged. Each individual's narrative was
examined independently to assess the coherence of each account. Data
collection and analysis continued concurrently, according to constant
comparison methods of grounded theory, in which data are examined for
similarities and differences within themes, retaining the context of
the discussion and characteristics of the individuals to aid
understanding and allow interpretation and the development of
explanations of findings.27
Treatment in the CLasP study was allocated to each patient after he had
given written informed consent and completed questionnaires and
clinical tests, and was done by clinical researchers opening consecutive opaque envelopes. Patients were given an information sheet
that described the study as a randomised controlled trial and said that
it involved comparing treatments, that one treatment was new (laser
therapy), that there was uncertainty about which treatment was best,
and that allocation would be by chance and by a clinician opening a
sealed envelope.
The results relating to the experience and understanding of
randomisation are presented below according to the themes which emerged
from the interview data, although space does not permit detailed
descriptions of the context surrounding these data. Illustrative quotations are provided, selected for their relevance to the themes and
so that the reader can judge the interpretations of the researchers. Names have been changed to protect confidentiality.
Understanding randomisation
![]()
Abstract
Top
Abstract
Introduction
Patients and methods
Results
Discussion
References
Design In this exploratory study, which used
qualitative research methods, in-depth, semistructured interviews were carried out with 20 participants from the CLasP randomised controlled trial. Interviews were recorded on audio tape and fully transcribed. Data were analysed by comparing transcripts and describing emergent themes, using a grounded theory approach.
Setting The CLasP study comprises three linked
multicentre, pragmatic randomised controlled trials evaluating the
effectiveness and cost effectiveness of laser therapy, standard
surgery, and conservative management for men with lower urinary tract
symptoms or urinary retention, or both, related to benign prostatic
disease.
Subjects 20 participants in the CLasP study were
interviewed. Sampling was purposeful: men were included from each of
the treatment arms, the two major centres, and at different points in
the trial.
Interventions and outcome measures Interviews used a
checklist of topics to encourage participants to describe their experiences. Narratives concerning randomisation were compared to
identify common themes, retaining the context of the discussion to
allow detailed interpretation.
Results Most participants recalled and described
aspects of randomisation, such as the involvement of chance,
comparison, and concealed allocation. Many found the concept of
randomisation difficult, however, and developed alternative lay
explanations to make sense of their experiences. Inaccurate patient
information and lay interpretations of common trial terms caused
confusion.
Conclusions The provision of clear and accurate
patient information is important, but this alone will not ensure
consistent interpretation of concepts such as randomisation. Patients
may need to discuss the purposes of randomisation in order to
understand them fully enough to give truly informed consent.
Key messages
![]()
Introduction
Top
Abstract
Introduction
Patients and methods
Results
Discussion
References
![]()
Patients and methods
Top
Abstract
Introduction
Patients and methods
Results
Discussion
References
TURP)
for men with acute or chronic urinary retention; and laser, surgery,
and conservative management (monitoring without active intervention)
for men with lower urinary tract symptoms related to benign prostatic
disease. The aims of this substudy, to explore the perspectives of
patients who agreed or refused to participate in CLasP, meant that
qualitative research methods were most appropriate.22
![]()
Results
Top
Abstract
Introduction
Patients and methods
Results
Discussion
References
Almost all the participants were aware of some aspects of
randomisation, and most (14/20) acknowledged the involvement of chance
in the allocation of their treatment. Often this was transformed into a
description of other (lay) examples of chance, such as a lottery or
lucky dip: Mr Cooper: But anyway I agreed to
have a go at it, a bit of a lucky dip. She has them in envelopes, which
operation you are going to get, or which method of treatment you are
going to get. Mr Symonds: He said, oh yes you've got
a swollen prostate, you'll probably have to have an operation but
it's a chance you might take, which one of them you take, it comes out
the hat, sort of thing you know. It's out of the hat, you cannot pick.
that the doctor did not know what treatment was
best: Mr Murray: They were unbiased, didn't
give you any impression that one was better than the other. But the
scheme itself was
I think they wanted to compare, they wanted to do
all three and then make a comparison of what the end results were.
Explaining treatment allocation
The majority of men developed detailed narratives to describe and
explain their understanding of the method of treatment allocation.
While most were able to describe aspects of randomisation, such as the
involvement of chance, need for comparison, and concealed allocation,
often their narratives contained other lay explanations of what they
thought had happened or should have happened. Sometimes this was caused
by a clash between experience and expectation
for example, where they
had not seen the clinician open the envelope as expected:
Mr Mills: When she first explained it, she said
you'll be given an envelope and you take your pick, apparently, and
that never happened .... I never got offered
any envelope. I was just ... that was the treatment
they more or less picked out for me.
what do you call it
[laser therapy], this one where you're under management, but I think
it would be even better if they were to tell you that they prefer, what
you're going to get .... I think that would
be better than they let you take your pick when I think, along the
lines, that you know you're being conned. Mr Webster: Well
[randomisation] was a bit confusing. It was. They know what's wrong
with us. I thought it would just be one operation and that was it. If
it was an operation, or if they could have cured it by medication, they
would have decided there and then. The other consultant would have
decided
you know, this lad need medication, or, yes, this lad needs
the operation. KF: Did that surprise you? Mr Webster: Yes it did
actually, it did. I could understand it, but I couldn't realise, cope
with the idea that whatever the symptoms were, that was the envelope we
were going to get .... I just thought that
... if it wasn't too bad, I would get the medication
... but it just seems that they're tossing a coin in
the air.
Other common lay views revolved around the influence of
fate, luck, and trust: Mr Grange: I must say
that I was fairly convinced that I was going to get a laser operation.
I don't feel at all that those envelopes had anything to do with
it. Mr Cooper: I preferred the one that I got, so I must
have been lucky.
Although the majority of men were able to discuss
randomisation, two patients, both from the same centre and randomised
to laser therapy, did not believe that their allocation was different from normal clinical practice. Apart from these two, levels of knowledge about randomisation and development of alternative accounts were similar between centres and across treatment arms.
Meanings of trial terms
Another complicating issue was the lay understanding of common
terms often used by trialists with specific meanings but which have
other meanings outside the confines of randomised controlled trials,
such as "trial" and "random." In lay language, the word trial
means something that is tried out, while "at random" relates to
things being done without purpose: Mr Bowler:
She said there was three options which I had already read about. One
was tablets, one was the ordinary operation, and one was laser. I didn't really realise that it was this scheme whereby they were, a
trial, you know. Because I didn't think the other one is a
trial
TURP. It's longstanding, isn't it? Mr Flint: Well,
I suppose there's a random system. There isn't a better way really. I
mean, if it was just done randomly like that without anybody looking to
see how certain results had gone and say "oh well, we'll take that one for there, we'll do this one there." If it was done randomly like that, then I suppose it's as good as any.
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Discussion |
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Randomisation and treatment allocation
Most patients were able to describe some aspects of the concept of
randomisation, particularly in terms of the involvement of chance, with
some having a more detailed understanding of treatment comparison,
concealed allocation, and experimental design. In response to a
structured questionnaire about randomisation, most would probably have
been shown to understand the concept in these basic terms. Qualitative
research has shown that individuals routinely attempt to make sense of
events by interpreting them in the context of their existing
beliefs.
28 29
In attempting to make sense of their
participation in this trial, these men produced narratives which on the
one hand described their understanding of elements of randomisation,
but on the other hand challenged these understandings with, for
example, accounts about trusting clinicians to make treatment
allocations on the basis of individual clinical characteristics.
not from a lack of
understanding of randomisation.
Information and consent
The terminology used in trials can have different meanings to
participants and trialists. The lay definition of "random" (see Mr
Flint), implies that treatments are allocated without purpose or
control. Similarly, "trial" means that something is being "tried
and tested" (see Mr Bowler). Mr Bowler is able to believe that laser
therapy is "on trial" but has difficulty with the idea that the
standard operation, TURP, is still "on trial." Similar lay
definitions have been found elsewhere.
20 21
Conclusion
Although this study confirms the importance of providing clear and
accurate patient information, it also shows that this in itself is
unlikely to ensure consistent interpretation of concepts such as
randomisation by participants. The patient information in this study
was well received and largely accurately recalled, but patients still
struggled with the concepts underlying the design and sometimes
developed coexisting contradictory accounts. It may be that
participants need to discuss the reasons for particular methods of
trial design (such as randomisation) with researchers and reflect on
these in order to understand them fully enough to give true informed
consent. It is not clear, however, whether this greater understanding
would lead to higher or lower levels of accrual to trials, but such an
investigation could be linked with research attempting to incorporate
patient preferences into randomised controlled
trials.
15 16
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Acknowledgments |
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We acknowledge the support of the clinicians involved in the CLasP trial and thank the participants for agreeing to be interviewed for this study.
JD initiated the study. KF carried out the interviews and data analysis. JD confirmed the accuracy of the data analysis. JD and KF wrote and are guarantors for the paper.
Funding: This study was funded by the Medical Research Council as a PhD studentship. The CLasP study was funded by the South and West and Northern Regional Research and Development Directorates.
Competing interests: None declared.
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References |
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(Accepted 1 October 1998)
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