The nature of medical evidence and its inherent uncertainty for the
clinical consultation: qualitative study
Frances Griffiths, Eileen Green, Maria Tsouroufli
Objective To describe how clinicians deal with the uncertainty
inherent in medical evidence in clinical consultations.
Design Qualitative study.
Setting Clinical consultations related to hormone replacement
therapy, bone densitometry, and breast screening in seven
general practices and three secondary care clinics in the UK
Participants Women aged 45-64.
Results 45 of the 109 relevant consultations included sufficient
discussion for analysis. The consultations could be categorised
into three groups: focus on certainty for now and this test, with
slippage into general reassurance; a coherent account of the
medical evidence for risks and benefits, but blurring of the
uncertainty inherent in the evidence and giving an impression
of certainty; and acknowledging the inherent uncertainty of the
medical evidence and negotiating a provisional decision.
Conclusion Strategies health professionals use to cope with the
uncertainty inherent in medical evidence in clinical
consultations include the use of provisional decisions that allow
for changing priorities and circumstances over time, to avoid
slippage into general reassurance from a particular test result,
and to avoid the creation of a myth of certainty.
Clinicians have access to a growing body of good clinical
research evidence informing them about the effectiveness of
many medical interventions. However robust the research, clini-
cians face the dilemma of applying this evidence to individual
patients.1This is the uncertainty inherent in the nature of medi-
cal evidence. For example, epidemiology tells us that smoking is
a risk factor for heart attack, but it does not tell us which
individuals will be affected.2Randomised controlled trials of hor-
mone replacement therapy3report on the number of extra
breast cancers identified in a large number of women receiving
treatment compared with those not receiving treatment,but they
cannot tell us which women will develop the extra cancers. This
dilemma between the nature of medical evidence and individual
patient care is central to medicine’s history and will not
disappear, as they are essential to each other. Diseases always
manifest themselves in patients’ bodies and minds, and in
seeking to understand, treat, and predict the outcome of disease,
clinicians need to move their focus from the individual to more
Clinicians recognise this dilemma and have reflected on this
in relation to their clinical practice2and the need for research
methods that give more attention to the particular rather than to
the general.5The importance of this dilemma is discussed within
related disciplines, including medical philosophy, ethics, and
health policy.6–9Few studies, however, have examined what clini-
cians actually say to patients.10Studies have considered how
clinicians communicate clinical evidence to patients, taking
account of their preferences11and maintaining the clinician-
patient relationship.12Studies have also acknowledged the
difficulty of communicating about the risks and benefits of inter-
ventions.13These studies do not, however, examine communica-
tion in relation to the inherent uncertainty in the evidence. We
examined how health professionals talk to patients about this
uncertainty, and we provide a framework for reflecting on how
they handle the dilemma of applying clinical evidence to
We examined consultations with health professionals in both
primary and secondary care where there was discussion of one
or more of the interventions of hormone replacement therapy,
bone densitometry, or breast screening. Our study included
healthcare sites in contrasting socioeconomic contexts in the
Midlands and north east England. The collection of these data
was part of a larger study, reported elsewhere.14 15
All women aged 45-64 attending one of seven general prac-
tices or three specialist clinics in the UK NHS were invited to
participate in our study. After consent was obtained, the health-
care professional audiotaped the consultations. These were
reviewed for their relevance to our study. We discarded those
with no mention of the relevant interventions, and we retained
all the others regardless of the extent of the discussion of the
interventions. Table 1 lists the details of the clinics and surgeries
and consultations recorded. The details of the research process,
including analysis, are on bmj.com.
Overall, 109 consultations were relevant: 73 from general
practice and 36 from specialist clinics.Most women attending the
clinics agreed to be recorded, whereas in general practice the
consent rate was lower (20% in some practices).
A key emergent theme was uncertainty and how it is
discussed between health professionals and women, particularly
the uncertainty inherent in medical evidence when it is applied
to particular patients. The data included 64 consultations with
only a brief mention of the interventions. For example, a woman
discusses with the practice nurse those symptoms she thinks are
due to the menopause, and hormone replacement therapy is
Details of the research process are on bmj.com
Cite this article as: BMJ, doi:10.1136/bmj.38336.482720.8F (published 31 January 2005)
BMJ Online First bmj.com
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health professionals because they feel vulnerable at that time or
because they believe the myth of medical certainty. Health
professionals are in a position of influence with patients, so in
responding to a desire for certainty they should critically reflect
on the effect this may have on their patient now and in the future,
such as building an expectation of certainty of outcome from
medical interventions. The assessment of how much to
emphasise certainty or not for each patient should be explicit in
the training of medical communication skills.
In the consultations where a provisional decision was made,
negotiation was present between the health professional and
woman. How much it was guided by the woman and how much
by the health professional varied (see box 4).Data from the study
shows that women vary in their preference for involvement in
decision making with health professionals, and that this varies
according to their circumstances.15It is the provisional nature of
the decision, rather than the woman’s involvement in the
decision, that seems to allow the decision to sit comfortably with
acknowledging the uncertainty inherent in medical evidence.
In general practice in the United Kingdom, it is possible to
make provisional decisions with patients and to review them. It
provides continuity of care for individuals,21of which this
decision making process is one aspect. In contrast, specialists
may see patients only once or review their treatment only at
infrequent intervals making it more difficult to negotiate
provisional decisions.The challenge for health professionals is to
develop the skills to acknowledge uncertainty and to negotiate
provisional decisions, including when considering test results or
starting new interventions.
The major types of evidence used in clinical medicine cannot
be directly applied to an individual, so health professionals will
continue to face the dilemma this creates. Through the teaching
of training in communication skills and the design of healthcare
systems it is important to enable health professionals to make
provisional decisions with individual patients. This approach to
decision making has the most potential for a continuing
acknowledgment of the inherent uncertainty in medical
evidence, an uncertainty which will remain even with progress in
basing medical interventions on robust research evidence.
We thank the participants for their time, the Leicester Warwick Medical
School GP Lecturer Group, the University of Warwick Academic GP Regis-
trar Group, the University of Warwick Primary Care Research User Group
for their contribution to the study, and the reviewers for their suggestions.
Contributors: FG was principal investigator for the study. EG was
coapplicant on the study funding proposal, managed a study field site, and
contributed to each stage of the study development, process, analysis, and
coapplicants on the study funding proposal, contributed to the design of
the study, advised on the conduct of the study, and contributed to analysis
and reporting. Di Thompson and MT undertook the data collection and
contributedto analysisand reporting.
Lindenmeyer contributed to analysis.
Funding: Economicand Social
(L218252038); part of the innovative health technology programme.
Competing interests: None declared.
Ethical approval: Warwickshire local research ethics committee and Hartle-
pool and North Tees local research ethics committee.
Kathryn Backett Milburn were
Pamela Lowe andAntje
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(Accepted 9 December 2004)
Centre for Primary Health Care Studies, University of Warwick, Coventry CV4
Frances Griffiths senior clinical lecturer
Centre for Social and Policy Research, University of Teesside, Middlesbrough TS1
Eileen Green professor
Institute for Society, Health and Ethics, University of Cardiff, Cardiff CF10 3AT
Maria Tsouroufli research fellow
Correspondence to: F Griffiths email@example.com
What is already known on this topic
Uncertainty about outcome for an individual patient is
intrinsic to the nature of medical evidence
This creates a dilemma that will always be present
Communicating evidence to patients is a key part of clinical
consultations, with a growing evidence base of how it is best
What this study adds
A dilemma for health professionals is creating a myth of
certainty around what is inherently uncertain
This may be avoided by negotiating provisional decisions
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