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Narrative based medicine: Narrative based
medicine in an evidence based world
Trisha Greenhalgh
BMJ
1999;318;323-325
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Education and debate
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Narrative based medicine
Narrative based medicine in an evidence based world
Trisha Greenhalgh
This is the last
in a series of
five articles on
narrative based
medicine
In a widely quoted riposte to critics who accused them
of naive empiricism, Sackett and colleagues claimed
that “the practice of evidence based medicine means
integrating individual clinical expertise with the best
available external clinical evidence .... By individual
clinical expertise we mean the proficiency and
judgment that individual clinicians acquire through
clinical experience and clinical practice.” 1 Sackett and
colleagues were anxious to acknowledge that there is
an art to medicine as well as an objective empirical sci­
ence but they did not attempt to define or categorise
the elusive quality of clinical competence. This article
explores the dissonance between the “science” of
objective measurement 2 and the “art” of clinical
proficiency and judgment, 3–5 and attempts to integrate
these different perspectives on clinical method.
Summary points
Even “evidence based” clinicians uphold the
importance of clinical expertise and judgment
Clinical method is an interpretive act which draws
on narrative skills to integrate the overlapping
stories told by patients, clinicians, and test results
Department of
Primary Care and
Population
Sciences, Royal Free
and University
College London
Medical School,
London N19 5NF
Trisha Greenhalgh,
senior lecturer
p.greenhalgh@ucl.
ac.uk
Series editor:
Trisha Greenhalgh
The art of selecting the most appropriate medical
maxim for a particular clinical decision is
acquired largely through the accumulation of
“case expertise” (the stories or “illness scripts” of
patients and clinical anecdotes)
The dissonance we experience when trying to
apply research findings to the clinical encounter
often occurs when we abandon the
narrative­interpretive paradigm and try to get by
on “evidence” alone
The limits of objectivity in clinical method
Science is concerned with the formulation and
attempted falsification of hypotheses using reproduc­
ible methods that allow the construction of generalis­
able statements about how the universe behaves.
Conventional medical training teaches students to view
medicine as a science and the doctor as an impartial
investigator who builds differential diagnoses as if they
were scientific theories and who excludes competing
possibilities in a manner akin to the falsification of
hypotheses. This approach is based on the somewhat
tenuous assumption that diagnostic decision making
follows an identical protocol to scientific inquiry—in
other words, that the discovery of “facts” about a
patient's illness is equivalent to the discovery of new
scientific truths about the universe.
The evidence based approach to clinical decision
making is often incorrectly held to rest on the assump­
tion that clinical observation is totally objective and
should, like all scientific measurements, be reproduc­
ible. Tannenbaum summarised this view in 1995:
“Evidence­based medicine argues for the fundamental
separability of expertise from expert and of knowledge
from knower, and the distillation of medical truth out­
side the clinical encounter would seem to allow both
buyers and sellers in the health care market to act
independently and rationally.” 6
Although many disciples of the evidence based
medicine movement (perhaps especially those with a
management, rather than a clinical, background) might
support this positivist image of evidence based
practice, its founding fathers made no such claim for
the objectivity of clinical method. Indeed, it was Sackett
and his colleagues who found that whenever the diag­
nostic acumen of doctors is studied, different clinicians
show a singularly unimpressive amount of agreement
beyond chance. 7 Sackett et al argued that we should
acknowledge and measure the amount of disagree­
ment between different clinicians in different circum­
stances
BMJ 1999;318:323–5
inexperience or incompetence. Clinical agreement,
expressed statistically as the
score, is of the order of
50% beyond chance for routine clinical procedures
such as detecting the presence or absence of pulses in
the feet, classifying diabetic retinopathy as mild or
severe, and assessing the height of the jugular venous
pressure. (Incidentally, cardiologists agreed rather
more often than this in diagnosing angina from
patients' descriptions of chest pain and, in some
studies, rather less often in interpreting the abstracted,
hard reality of electrocardiographic tracings. 7 )
Those who have studied the phenomenon of clini­
cal disagreement, as well as those of us who practise
medicine in a clinical setting, know all too well that
clinical judgments are usually a far cry from the objec­
tive analysis of a set of eminently measurable “facts.”
Pitting oedema, for example, will be more readily
detected in a patient who has just mentioned that she
ran out of “water tablets” last week than in someone
who has made no such comment.
In the language of empiricism such an observation
could be interpreted as ascertainment bias, but in the
language of social constructionism it reflects the
notion that even objective facts are theory laden. 8 Our
medical training can be viewed as a kind of deductive
narrative that predicts the fact of pitting oedema for
which the trained clinical mind is then prepared.
Evidence supports the claim that doctors do not simply
assess symptoms and physical signs objectively: they
interpret them by integrating the formal diagnostic
criteria of the suspected disease (that is, what those dis­
eases are supposed to do in “typical” patients as
described in standard textbooks) with the case specific
features of the patient's individual story and their own
accumulated professional case expertise.
ê
rather
than
dismiss
it
or
attribute
it
to
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“wrong” answers to particular clinical questions, it is
often impossible to define a single “right” one that can
be applied in every context.
Integrated diagnostic judgments:
evidence within the interpreted story
The box shows a comment made by a general
practitioner in Cardiff, cited in a lecture by Nigel Stott,
which I have expanded into a hypothetical example
about Dr Jenkins. Meningococcal meningitis was
diagnosed against the odds on the basis of two very
non­specific symptoms and what was, on the face of it, a
lucky hunch; the general practitioner who made the
diagnosis had seen meningococcal meningitis only once
in 96 000 consultations. Consider the decision sequence
in this encounter: Dr Jenkins contemplates the brief his­
tory hastily obtained by the receptionist over the
telephone and, using his intimate knowledge of the
family, begins to put together the story of this illness.
One interpretation of this doctor's action is that he
subconsciously compared the script so far with the tens
of thousands of “illness scripts” from children over the
years who had become (or were perceived to have
become) acutely ill and decided that this script didn't fit
with the template “nothing much the matter.” The
word “strangely” is rarely used by parents to describe
the manifestations of non­specific illness in young chil­
dren (compare the familiar expressions “off colour,”
“not herself,” “poorly,” “washed out,” all of which
occupy a very different semantic space from
“strangely” 17 ). It may be this single word that alerted the
doctor to the seriousness of the case.
Of the many medical maxims (rules of thumb) that
come to mind when trying to make sense of this story,
Dr Jenkins might have taken particular note of the sec­
ond and fifth maxims presented in the box to inform
his decision making. This doctor's skill, which would be
extremely difficult to measure formally, was to
integrate judiciously selected best evidence (for exam­
ple, on the prognosis of early meningococcal meningi­
tis with and without the urgent administration of
penicillin) with the potential significance of the word
“strangely” and his personal knowledge about this
family (their uncomplaining track record, the mother's
Diagnosis: evidence or the interpreted
story?
We all know that anecdotal experience, the material of
traditional medical practice and teaching, 9 is unrepre­
sentative of the average case 10 11 and thus a potentially
biased influence on decision making. 12 Evidence based
clinical decision making involves the somewhat counter­
intuitive practice of assessing the current problem in the
light of the aggregated results of hundreds or thousands
of comparable cases in a distant population sample,
expressed in the language of probability and risk—the
stuff of clinical epidemiology 7 and bayesian statistics. 13
How, then, can we square the circle of upholding
individual narrative in a world where valid and gener­
alisable truths come from population derived evi­
dence? My own view is that there is no paradox. In
particle physics the scientific truths (laws) derived from
empirical observation about the behaviour of gases fail
to hold when applied to single molecules. Similarly
(but for different reasons), the “truths” established by
the empirical observation of populations in ran­
domised trials and cohort studies cannot be mechanis­
tically applied to individual patients (whose behaviour
is
irremediably
contextual
and
idiosyncratic)
or
episodes of illness.
In large research trials the individual participant's
unique and multidimensional experience is expressed
as (say) a single dot on a scatter plot to which we apply
mathematical tools to produce a story about the
sample as a whole. The generalisable truth that we seek
to glean from research trials pertains to the sample's
(and, hopefully, the population's) story, not the stories
of individual participants. There is a serious danger of
reifying that population story—that is, of applying what
Whitehead called the fallacy of misplaced
concreteness 14 —and erroneously viewing summary sta­
tistics as hard realities.
Misplaced concreteness is also an apt description
of the dissonance we experience when we try to apply
research evidence to clinical practice. Hunter has sug­
gested that the reason why medical practice cannot
constitute a science is that medicine lacks rules that can
be generally and unconditionally applied to every case,
even every case of a single disease. 15 This is borne out,
for example, by Tudor Hart's observation that only
10% of patients in primary care have the sort of
isolated, uncomplicated form of hypertension that
lends itself to management by a standard evidence
based guideline. 16
Dr Jenkins's hunch
“I got a call from a mother who said her little girl had
had diarrhoea and was behaving strangely. I knew the
family well, and was sufficiently concerned to break off
my Monday morning surgery and visit immediately.”
Maxims that might be considered in this case:
·
We cannot commit ourselves completely and
immediately to all patients who seek our help
·
If meningococcal meningitis is suspected the doctor
must act urgently and make the patient a priority
·
Diarrhoea in previously well children is generally
viral and self limiting
·
Meningococcal meningitis produces a characteristic
rash and neck stiffness
·
Meningococcal meningitis presents non­specifically
in primary care
Hence, although there are certainly
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Education and debate
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good sense, and the memory of the child as one whose
premorbid behaviour had been nothing out of the
ordinary). Taken alone, neither best research evidence
nor the intuitive response to a short but unusual story
would have saved this patient, but the integrated appli­
cation of both has produced a feat we would all be
proud to replicate just once in our clinical careers.
The well documented frustration that health
professionals experience when trying to apply evidence
based research findings to real life case scenarios occurs
most commonly when they abandon the interpretive
framework and attempt to get by on evidence alone. 18–20
Such a situation might have occurred if Dr Jenkins had
suspended his clinical judgment and adhered exclu­
sively to the letter of a guideline on the early diagnosis
and treatment of meningitis.
do next and the enactment of that narrative. 23 Should
the doctor order further tests, treat (if so, with what?),
refer to a specialist colleague, or watch and wait? The
increasing recognition that these decisions should
arise out of informed dialogue between doctor and
patient 24 has shown that there is a need for further
research into the narrative of shared decision
making 25 —an aspect of narrative analysis in medicine
that will no doubt expand over the next few years.
Conclusion
Appreciating the narrative nature of illness experience
and the intuitive and subjective aspects of clinical
method does not require us to reject the principles of
evidence based medicine. Nor does such an approach
demand an inversion of the hierarchy of evidence so
that personal anecdote carries more weight in decision
making than the randomised controlled trial. Far from
obviating the need for subjectivity in the clinical
encounter, genuine evidence based practice actually
presupposes an interpretive paradigm in which the
patient experiences illness in a unique and contextual
way. Furthermore, it is only within such an interpretive
paradigm that a clinician can meaningfully draw on all
aspects of evidence—his or her own case based experi­
ence, the patient's individual and cultural perspectives,
and the results of rigorous clinical research trials and
observational studies—to reach an integrated clinical
judgment.
Stories within stories
The doctor­patient encounter takes place in a highly
structured transactional space, in which the behaviour
of both parties is determined by socialised expecta­
tions. In the American philosopher Leder's view, the
“text” that constitutes the diagnostic encounter, and
which distinguishes it from other human narratives or
modes of communication, is a story about the “person
as ill.” 21 This in turn integrates four separate secondary
texts:
x
the experiential text—the meaning the patient
assigns to the various symptoms, deliberations, and lay
consultations in the run up to the clinical encounter (a
subject eloquently explored by Heath 22 );
x
I thank the many colleagues who commented on earlier drafts
of this article, in particular Dr Brian Hurwitz and DrJAMuir
Gray. The views expressed are mine alone.
the narrative text—what the doctor interprets to be
“the problem” from the story the patient tells—the tra­
ditional medical history;
x
1 Sackett DL, Rosenberg WMC, Gray JAM, Haynes RB, Richardson WS.
Evidence based medicine: what it is and what it isn't. BMJ 1996;312:71­2.
2 Popper K. Conjectures and refutations: the growth of scientific knowledge. New
York: Routledge and Kegan Paul, 1963.
3 McWhinney IR. Medical knowledge and the rise of technology. J Med
Philos 1978;3:293­304.
4 Tannenbaum SJ. What physicians know. N Engl J Med 1993;329:1268­71.
5 Hunter KM. Narrative, literature, and the clinical exercise of practical rea­
son. J Med Philos 1996;21:303­20.
6 Tannenbaum S. Getting there from here: evidentiary quandaries of the
US outcomes movement. J Eval Clin Pract 1995;1:97­103.
7 Sackett DL, Haynes RB, Guyatt GH, Tugwell P. Clinical epidemiology: a basic
science for clinical medicine. London: Little Brown, 1991.
8 Fish S. Doing what comes naturally: change, rhetoric, and the practice of theory
in literary and legal studies . Durham, NC: Duke University Press, 1995.
9 Macnaughton J. Anecdote in clinical practice. In: Greenhalgh T, Hurwitz
B, eds. Narrative based medicine: dialogue and discourse in clinical practice .
London: BMJ Books, 1998:202­11.
10 Kahneman D, Slovic P, Tverskey A. Judgement under uncertainty: heuristics
and biases . Cambridge: Cambridge University Press, 1982.
11 Plous S. The psychology of
the physical or perceptual text—what the doctor
gleans from a physical examination of the patient
(using the ill defined but recognisable set of skills that
have been called “practical reason” 5 ); and
x
the instrumental text—what the blood tests and x
rays “say.”
In the instrumental text, “machines are employed
to co­author a fuller story.” 22 The shadow on the chest
radiograph of a 19 year old student returning from an
overland trip across India may be objectively identical
to that of a 56 year old smoker who has never been out
of Sweden. Both may have coughed up blood. But the
radiologist who looks at the x ray films “sees” tubercu­
losis in one and a high probability of cancer in the
other. According to Leder, the search for the
“objective” analysis of diagnostic tests (for example,
looking at an x ray film without a clinical or social his­
tory) is a flight from interpretation, and one that is
doomed to fail. 21 This prediction from a hermeneutic
perspective resonates strongly with the call from
evidence based circles for the “truth” of the instrumen­
tal text (that is, the results of diagnostic tests) to be
interpreted judiciously on the basis of bayesian pretest
probabilities determined by the history and physical
examination (for example, how likely on clinical
grounds the patient is to have a particular condition). 7
Leder's analysis and much of what has been written
on the narrative stream in clinical medicine, centres on
the diagnostic sequence, thus addressing only the first
part of the clinical encounter. But there is also a thera­
peutic narrative: the formulation of a plan of what to
judgment and decision making. New York:
McGraw­Hill, 1993.
12 Dawson NV, Arkes HR. Systematic errors in medical decision making:
judgement limitations. Med Decis Making 1987;2:183­7.
13 Freedman L. Bayesian statistical methods. BMJ 1996;313:569­70.
14 Whitehead AN. Science and the modern world . New York: Free Press, 1925.
15 Hunter K. “Don't think zebras”: uncertainty, interpretation, and the place
of paradox in clinical education. Theor Med 1996;17:225­41.
16 Tudor Hart JT. Hypertension guidelines: other diseases complicate man­
agement. BMJ 1993;306:1337.
17 Osgood C, May WH, Murray S. Cross­cultural universals of affective meaning .
Urbana, IL: University of Illinois Press, 1975.
18 Grimley Evans J. Evidence­based and evidence biased medicine. Age
Ageing 1995;25:461­4.
19 Asch DA. Why some health policies don't make sense at the bedside.
Ann Intern Med 1995;122:846­50.
20 Greenhalgh T. Evidence­based medicine. In: Hall M, Dwyer D, Lewis T,
eds. GP training handbook . 3rd ed. Oxford: Blackwell Scientific, 1998.
21 Leder D. Clinical interpretation: the hermeneutics of medicine. Theor Med
1990;11:9­24.
22 Heath I. The mystery of general practice. London: Nuffield Provincial Hospi­
tals Trust, 1995:17­21.
23 Mattingly C. The concept of therapeutic emplotment. Soc Sci Med
1994;34:811­22.
24 Stewart M. Patient centred medicine. London: Sage, 1995.
25 Elwyn GJ. Shared decision making in primary care . Cardiff: Welsh Office,
1997.
The articles in this
series are adapted
from Narrative
Based Medicine ,
edited by Trisha
Greenhalgh and
Brian Hurwitz,
and published by
BMJ Books.
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