4/13/2015
Analytical versus non-analytical
clinical reasoning
Alireza Monajemi, MD-PhD
Philosophy of science department
Institute for Humanities and Cultural Studies
Monday, April 13, 2015
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Monday, April 13, 2015
EBM- weekly conference
Monday, April 13, 2015
EBM- weekly conference
Dual process theory
Non-analytical=system 1
• Unconscious, automatic
• Pattern recognition
• Rapid, computationally
powerful, massively parallel
• Pragmatic
• Not linked to working
memory
Monday, April 13, 2015
Analytical=system 2
• consciousness
• Slow and sequential
• Abstract and hypothetical
thinking
• High effort
• Linked to working memory
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The importance of clinical reasoning
The maintenance of clinical teaching
expertise requires, in part, an
understanding of strategies expert
clinicians use, often unconsciously, to
reason through diagnostic case
presentations.
Monday, April 13, 2015
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The psychological mechanisms
underlying such reasoning
tendencies are not always
available to
introspection
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instructional techniques for
• Maximizing the probability that
students will become successful medical
problem solvers and on strategies for
accurately diagnose
• assessing whether or not students have
in fact developed the required
competencies
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Approach to clinical case
A 56 year-old man consults you because of
pain in his left leg began 2 days ago and has
been getting progressively worse. He states his
leg is tender below the knee and swollen
around the ankle. History of recent surgery
and immobilization is positive. He has never
had similar problems. No dyspnea. His other
leg is OK.
4/13/2015
Analytical reasoning
One need not look very far to
recognize that medical educators
have traditionally focused on what
are known as ‘analytic’ models of
clinical reasoning.
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Analytical reasoning
careful analysis of the relation
between signs and symptoms and
diagnoses are the hallmark of
clinical expertise
Monday, April 13, 2015
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Analytical reasoning
Generation of a differential list of
relevant diagnoses and
application of an appropriate
diagnostic algorithm then allows
each diagnosis to be weighted in
terms of its relative probability
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Analytical reasoning
clinical teacher admonishes a
student to ‘be objective’ and
‘carefully consider all the
evidence available before
generating diagnostic
hypotheses’.
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Analytic process in clinical reasoning
Monday, April 13, 2015
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Analytical reasoning
• these models assume that physicians are
aware of the a priori probability with which a
particular diagnosis may present and the
conditional probability associating each piece
of evidence (e.g. signs, symptoms and
diagnostic tests) with the diagnosis
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Analytical reasoning
• close to the evidence-based medicine
movement
• Bayes’theorem or regression analyses
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Non-analytical reasoning
• Solving problems in the light of
prior knowledge and belief
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Non-analytical reasoning
• the evidence that clinicians use
non-analytic processes in
reaching diagnostic decisions is
indisputable
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Non-Analytic process in clinical
reasoning
Monday, April 13, 2015
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Non-analytical reasoning
It has been argued that the
ability to use non-analytic
bases of clinical decision
making increases with
expertise
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as a result, the use of pattern recognition
should not be advocated among
medical students
for fear of
potentially grim consequences
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Non-analytical reasoning
Non-analytic bases of
judgment are not inferior
to more analytic forms of
reasoning
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clinical teachers should
inform their students that
similarity to past instances
can serve as a useful guide.
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excessive reliance on nonanalytic approaches to clinical
reasoning can be a source of
diagnostic error
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• Where does this leave the clinical
teacher? First, it must be
recognized that these two forms
of processing are not mutually
exclusive.
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• It is highly probable that both
forms of processing contribute to
the final decisions reached in all
cases (for both novices and
experts).
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A combined model of clinical reasoning
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A critical factor
, however,
was that the analytic
processing should be carried out in close
temporal relation
to performing the actual task of diagnostic
judgment.
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• Non-analytic processing is expected to
dominate during the initial phases of
considering a new case
• Analytic processing is expected to play a
dominant role in hypothesis testing
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Non-analytic processing
is expected to dominate
during the initial phases of
considering a new case
Monday, April 13, 2015
Analytic processing
is expected to play a dominant
role in hypothesis testing
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These two reasoning
are complementary contributors to
the overall accuracy of the clinical
reasoning process,
each influencing the other
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combined instruction
resulted in greater
diagnostic accuracy than
did purely analytic
instruction
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failure to perform an
analytic confirmation
results in
premature closure
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“good problem solvers”
=
“good coordinators” of
analytic and non-analytic
processing
Monday, April 13, 2015
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Dual process theory
Non-analytical=system 1
• Unconscious, automatic
• Rapid, computationally
powerful, massively parallel
• Pragmatic (contextualizing
problems in the light of
prior knowledge and belief)
• Low effort
• Not linked to working
memory
Monday, April 13, 2015
Analytical=system 2
• reflective consciousness
• Slow and sequential
• Abstract and hypothetical
thinking
• Controlled and responsive
to instruction and stated
intentions
• High effort
• Linked to working memory
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Dual process theory
Two different kinds of cognitive
processing
affect
inferences and judgments.
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Critical thinking in medicine
is now
called
reflective practice in
medicine
Reflective practice in
medicine
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Reflective practice in medicine
has a multidimensional structure,
comparing five sets of behaviors
and reasoning processes that
require both cognitive and
affective skills.
1
Theoretical model of reflective
practice in medicine
•Deliberate Induction
2
•Deliberate deduction
3
•Test and synthesize
4
•Openness towards reflection
5
•Meta-reasoning
How to provoke analytical reasoning
(1) read the case again,
(2) write down the hypothesis previously indicated
again,
(3) list findings that support this hypothesis,
(4)list t findings that oppose it, and
(5) list findings that would be expected if the
hypotheses at-hand 'would be true but that were not
encountered in the particular case
(6) to list alternative hypotheses if the first one they
considered would prove to be incorrect.
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How to provoke analytical reasoning
For each on e of these they were then asked to follow the
same procedures:
(7) listing findings consistent with the hypothesis,
(8) those that contradict it, and
(9) those that were expected but not present in the case.
Based on this analysis,
(10) to indicate their conclusions by ranking diagnostic
hypotheses in order of likelihood
(11) presenting a final diagnosis.
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Deliberate induction
• A tendency to search
alternative diagnoses in
response to difficult or
unexpected problems.
Deliberate induction
• Feelings of discouragement to continue exploring the problem when initial hypothesis
refuted by findings of investigation .
• Viewing exploration of signs and symptoms that are not compatible with the conjectures
made about a patient's problem as a worthwhile device for reaching a diagnosis.
• Experiencing feelings of disappointment when first diagnosis for a patient's problem
not confirmed by the findings of investigation .
• Considering that social and psychological factors, although seldom cause of disease,
Deliberate contribute to its exacerbation.
• Seeing reflection about a patient 's problem as goo d only for those physicians who can afford
the time to do it.
• Percept ion of certainty about evidence of effectiveness of prescribed measures due to
recent literature review.
• Undertaking initiatives to modifying practice's procedures and/or routines in order to allow
solutions to patient's problems, when their management required those adjustments.
• Discussing/ looking for consultation with colleagues led by difficulties perceived in managing
a case.
Deliberate deduction
• Explore signs & symptoms that
might present if any one of these
alternate hypotheses become
true. = Backward reasoning
Deliberate deduction
• Acknowledgment that had encountered patients to whom the
clinical appraisal didn't lead to diagnostic, who required a
differential diagnosis including the possibility of a severe
problem
• Designing a systematic plan for exploring all the hypotheses
formulated for the patient's problem, when a severe, difficult
problem was considered.
• Going straightforward the most complex exam, based on the idea
that it could quickly bring a conclusion about the severe disease
whose possibility had been considered
• Looking for additional information by reviewing literature when
dealing with cases with unexpected poor treatment outcomes.
• Discussing/looking for consultation with colleagues led by
difficulties perceive in managing a case
Test & Synthesize
• A willingness to test these
hypotheses and synthesize
new understandings about the
problem.
Test & Synthesize
• After having seen a patient he/she said to him/herself:
"What should I do differently next time "
• When a very complex case he/she has been dealing with
has reached its completion, he/she usually feels relieved
• He/she has faced uncomfortable or troublesome
situations generated by his/her
• He/she adjusted treatment in the light of knowledge
about feasibility of possible measures he/she had
acquired while dealing with previous similar patients.
• He/she used his/her experience with similar patient s in
the past to assess feasibility of the measures he/she was
considering for the treatment.
Openness to reflection
• Engage in reflective reasoning in
response to changing problems
• Tolerate uncertainty and
ambiguity
Openness to reflection
• Experiencing feelings of distress when encountering
difficult patients.
• Waiting and observing evolution of a patient to
whom clinical assessment did not lead to a diagnosis,
whenever possible.
• Mentally rehearsing, during the evenings. some of
the cases he/she had see n during the day.
• Having patients whose problems he/ she had
difficulties in understanding or managing g
• crossing his/her mind at a later stage.
• Considering own practice too busy. leaving only
limited time to reflect on cases he/she is dealing
with.
Meta-reasoning
• Capability to reflect about one’s
own thinking processes
• Meta-cognition
Meta-reasoning
• Questioning reasons underlying own decisions in order to
check how far they were patient-centered.
• Realizing that own assumptions with regards to a patient
problem could have distorted or restricted initial exploration
of the problem.
• Viewing him/herself as a quite successful physician.
• Experiencing cases in which he/she considered further
exploring the problem for defining a diagnosis was not
justifiable.
• Attempting to forget very difficult cases after their
completion.
• Reviewing specialist's approaches in referred case s in order
to verify what he/herself could have done in a better way.
Metacognition
Openness
Induction
Deduction
Test
Hypothesis
formation(DDx)
Backward
reasoning
Hypothesis
evaluation
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Reflective practice
&
medical errors
Monday, April 13, 2015
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‫‪Availability bias‬‬
‫تمایل به تشخیص ی که در به علت دیدن موارئ مشابه در زمان جدید‬
‫زود به ذهن خطور می‌کند‪ .‬پزشکی خانم ‪40‬ساله‌ای با درد ساق پای‬
‫ً‬
‫چپ را می‌بیند که نهایتا تشخیص میوسارکوما داده می‌شود‪ .‬او پس‬
‫از این هر بیماری با درد ساق پا را تشخیص میوسارکوم می‌دهد‪.‬‬
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‫‪Representativeness bias‬‬
‫تمایل پزشکان به اینکه تابلوی بالینی پروتوتیپیک را جستجو کنند بودن‬
‫توجه به اینکه به این نکته توجه کند که هر گردی‪ ،‬گردو نیست‪.‬‬
‫به عبارت دیگر اگر به تابلوی نادر یک بیماری روبرو شوند چون دنبال‬
‫ً‬
‫پرزنتاسیون شایع و پروتوتیپیک می‌گردند‪ ،‬آن را تشخیص نمی‌دهند‪.‬مثال‬
‫پزشکی در مرد میانسالی که با ‌درد شدید سردل مراجعه کرده است به‬
‫انفارکتوس میوکارد شک نمی‌کند و با تشخیص اولسر پپتیک ‌رانیتیدین‬
‫وریدی تجویز می‌کند‪.‬‬
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‫‪Overconfidence bias‬‬
‫یک تمایل عمومی است به اینکه بیشتر از آنچه عمل می‌کنیم می‌دانیم‬
‫پس به همین دلیل بر اسلس اطالعات اندک‪ ،‬یا ّ‬
‫شم یا شهود‬
‫تصمیمی می‌گیریم‪ Anchoring .‬و ‪ availability‬هر دو بسیار با‬
‫این خطا مربوط هستند‪ّ .‬‬
‫شم من می‌گوید این بیماری تشخیص‌اش‬
‫این است‪.‬‬
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‫‪Anchoring bias‬‬
‫تمایل به فیکس کردن ‪ ،first impression‬بر اساس عالئم و‬
‫ً‬
‫نشانه‌های بیمار دارند‪ .‬مثال خانم ‪ 70‬ساله که با کمردرد مراجعه‬
‫کرده است و در گرافی ‪ compression fracture‬دارد را با آنمی‬
‫نرموسیتیک تشخیص میلودیسپالستیک سندرم داده‌اند‪ .‬بدون توجه‬
‫به تشخیص‌های افتراقی مثل میلوم مولتیپل که تشخیص اصلی این‬
‫بیمار است‪.‬‬
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‫‪Premature closure‬‬
‫در پرتو در‬
‫پذیرفتن یک تشخیص بدون آنکه به طور کامل تائید شود ‌‬
‫ً‬
‫ّ‬
‫نظر گرفتن تشخیص‌های افتراقی‪ .‬مثال مرد‪ 55‬ساله سیگاری قهار و‬
‫پزشک‬
‫دیابتی که با استفراغ مقاوم به درمان مراجعه کرده است و ‌‬
‫با تشخیص گاستروپارزی دیابتی برای بیماری عکس ایستادۀ شکم‬
‫درخواست می‌کند که حبابهای هوا دیده می‌شود‪ .‬او بودن در نظر‬
‫گرفتن سایر علل ادو پاپی دوطرفه و آتاکس ی مرکزی بیمار را نادیده‬
‫می‌گیرد‪ .‬در س ی‌تی‌اسکن صورت گرفته در فوسای خلفی ضایعه دیده‬
‫می‌شود‪.‬‬
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‫‪Confirmation bias‬‬
‫تمایل به جستجوی عالئم و نشانه‌های تائید کنندۀ تشخیص ‌و‬
‫بی‌توجهی به سایر تشخیص‌ها‪.‬‬
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Experimental research in reflective
practice
Mamede, Schmidt, & Penaforte studt
Routine
Reflective
Experts
Nonreflective
Nonroutine
Routine
Nonroutine
• Reflective practices did not make a
DIFFERENCE ON ACCURACY OF DOAGNOSIS
IN simple cases.
• Reflective practices had a positive effect when
diagnosing complex cases.
• We need more research to explore the nature
of reflective practice in medicine.
• Doctors differs in the extent to which they
engage in reflective practices when faced with
complex clinical problems, ranging form very
reflective to virtually non-reflective doctors,
and these differences are measurable.
• The non-analytical, pattern-based clinical
reasoning characteristic of expert doctors,
although effective to solve routine cases, may
lead to higher of diagnostic errors in novel
complex situations.
• Reflective, analytical reasoning leads to higher
accuracy of diagnoses in difficult, ambiguous,
non-routine clinical problems, and enhancing
reflective practice can be assumed as a
strategy to minimize preventable medical
errors.
• The ideal clinical problem solving approach
entails combination of non-analytical and
analytical reasoning.
• The continuous growth of scientific medical
knowledge base, which nurtured the promise
of a systematic, objective, evidence-based
clinical practice, indeed has not reduced
uncertainty, ambiguity and complexity of
medical judgment.
Effects of RP
• Meta-cognition as a way to teach clinical
reasoning
• Deliberate practice should be continued
during practice that is changed the paradigm
of continuing education in medicine
• The way to reduce medical errors
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