Transcript Critical Thinking - Harvard University

Critical Thinking
Richard M. Schwartzstein, MD
Executive Director, Carl J. Shapiro Institute
for Education and Research
Faculty Associate Dean for Medical Education
Professor of Medicine
Harvard Medical School
Critical Thinking
• Do you do it?
Critical Thinking
• Do you do it?
• Do you teach it?
Critical Thinking
• Do you do it?
• Do you teach it?
• What is it?
Critical Thinking
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Do you do it?
Do you teach it?
What is it?
What is the relationship between
“critical thinking” and “clinical
reasoning?”
Who is this?
(How do you know?)
Who is this?
Who is this?
(How do you know?)
• Political leader of the 20th century.
• Mother was American, father was British
• Lost election after leading his country to
victory in war
• Fancied whiskey
Case
• A 60 year old man presents with a
complaint of shortness of breath
that has gradually worsened over 2
years. Now can only walk for 50
yards at which time he stops with a
sensation of “suffocating” and “urge
to breathe.” His wife notes
“wheezing” when this happens.
Case, cont.
• PH: asthma since childhood,
hypertension for 30 years, mild
diabetes, 30 pack year smoker
• PE: obese. BP 160/90, HR 92, RR 16
Mild increase in AP diameter of chest.
Lungs with mild decrease in air
movement, I/E=1/1.5; JVP=10 cm. +S4.
Abdomen benign. No edema.
Thoughts? What next?
Case, cont.
• Walk the patient:
After 50 yards, breathing starts to
become labored, patient appears
diaphoretic, chest exam: wheezes.
Diagnosis?
Cardiac Asthma
• Increased PCWP 
interstitial edema,
• Dyspnea
– Mechanical load
– Hypoxemia
– J-receptors
– Vascular
receptors
– “urge to breathe,”
“suffocating”
Diastolic Dysfunction
• 1/3 of cases of CHF
are due primarily to
diastolic dysfunction
• Failure of LV to
accommodate
increased volume
load
• Symptoms often
isolated to exercise
QUESTION
Is the patient an example to be
learned or a problem to be
solved?
QUESTION
Is the patient an example to be
learned or a problem to be solved?
Pattern recognition = experience-based,
non analytical reasoning
Norman G, Young M, Brooks L. Med Ed 2007
Primacy of Teaching
Objectives
If “critical thinking”
is one of our
objectives, we
have to
understand what
implications that
has for our
interactions with
students and
residents.
Critical Thinking
Plan of Attack
• Define the elements of critical
thinking
• Distinguish critical thinking from
clinical reasoning
• Delineate strategies for developing
critical thinking in our learners.
Critical Thinking
Plan of Attack
• Define the elements of critical
thinking
• Distinguish critical thinking from
clinical reasoning
• Delineate strategies for developing
critical thinking in our learners.
Caveat: this is a work in progress…
Hierarchy of Knowledge
Bloom’sTaxonomy, 1956
• Knowledge - What is
the most common
cause of...?
• Understand - If you
see this, what must
you consider…?
• Application - In this
patient, what is
causing…?
• Analysis,synthesis,
evaluation - critical
thinking?
Revision of Bloom’s Taxonomy
Anderson LW, Krathwohl DR (eds), 2001. A taxonomy for
learning, teaching and assessing: A revision of Bloom’s
taxonomy of educational objectives. New York, Longman.
What is an expert?
Mylopoulos M, Regehr G. Med Ed 2007
• Expertise = Knowledge + Experience
• Experts develop “rich and well organized
resources…to effectively and efficiently solve
routine problems of practice.”
• “Only some experts go beyond routine
competencies and display flexible, innovative
abilities…in a process of extending their
knowledge rather than applying it.”
Routine vs. Adaptive Expert
Mylopoulos M, Regehr G. Med Ed 2007
• Routine Expert
– Novel problem adapt problem to the
solution with which they are comfortable
– Characterized by speed, accuracy,
automaticity
• Adaptive Expert
– Use a new problem as a point of departure
for exploration; expand knowledge and
understanding
– Characterized by innovation, creativity
Critical Thinking
Is the KSA model appropriate?
• Are there specific:
– Knowledge/facts
– Skills
– Attitudes
…that must be
acquired in order
for the learner to
become a critical
thinker?
Knowledge
• Content learned
in a conceptual
framework
• How do the facts
fit together?
• What are the
underlying
mechanisms?
• What do you do
when the patterns
break down?
Knowledge
• Content learned
in a conceptual
framework
• Judge credibility
of sources
• From primary sources
to “Google it…”
• Primary sources
– Study design
– Appropriate
population
– Statistics
• Secondary sources
– Textbooks
– Review articles
• Evidence-based
medicine
Knowledge
• Content learned
in a conceptual
framework
• Judge credibility
of sources
• Bias and
cognitive
dispositions to
respond
• Availability biasprobability
assigned based
on ease of recall
of specific
examples
• Confirmation
bias - selectively
accepting or
ignoring data
Cognitive Dispositions to
Respond
Croskerry P, Acad Med, 2003, 78:775-780
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Fatigue
Team factors
Affective state
Ambient conditions
Past experience
Patient factors
Skills
• Formulation of
hypotheses
• How to pose
questions
– Going from the
particular to the
general
– Are they
testable?
– Revising with
new data
• Identifying the
key issues
Skills
• Formulation of
hypotheses
• Making logical
connections
between ideas
• Symptoms link
with physical
findings? Lab
data with
symptoms and
signs?
• Finding
common
mechanisms
Skills
• Formulation of
hypotheses
• Making logical
connections
between ideas
• Utilization of
data
• Sensitivity and
specificity of
tests
• Pre and posttest
probabilities
• Red flags
Skills
• Formulation of
hypotheses
• Making logical
connections
between ideas
• Utilization of
data
• Identify
assumptions
• Cultural
• Gender
• Contextual,
e.g., in our ED,
upper lobe
infiltrates are all
TB
Attitudes
• Open mind - willingness to consider
alternative explanations
• Awareness of one’s own cognitive
processes - what type of reasoning
was I using? (metacognition)
• Reflection - how did we go wrong?
Where did we make a mistake?
Critical Thinking vs Clinical
Reasoning
The Clinical Reasoning
Paradigm
• What do “experts” (routine experts?) do?
– Content knowledge vs thought process
– Mental representations of disease
processes
• Illness scripts (mini-patterns)
• Semantic qualifiers (e.g., acute vs
chronic, proximal vs distal)
• Encapsulated knowledge (one type of
knowledge embedded in other
knowledge - basic mechs within clinical
examples - example: “sepsis”)
How often do we need critical
thinking in the clinical setting?
• Bowen J, NEJM,
2006:355;2217-2225
– Pattern recognition
(non-analytical
thinking) is “essential
to diagnostic
expertise”
– “Deliberative analytic
reasoning is primary
strategy when a
case is complex…”
Clinical Reasoning and
Critical Thinking
Clinical Reasoning
My bias…
• The 80/20 rule
– 80% of clinical medicine, pattern
recognition works well.
– 20% of clinical medicine, to get it
right, you need to apply the
knowledge, skills, and attitudes of
critical thinking.
• The key - knowing into which group
your patient fits.
Can we teach critical
thinking?
Critical Thinking in College, Council for
Learning Assessment (CLA), courtesy of
Richard Hersh, EdD, lecture at HMS, Jan. 19, 2007
Some Strategies for Teaching
Critical Thinking
• Go back to the knowledge, skills,
attributes
–Be explicit that we are teaching
critical thinking
–Woven into teaching content
–Separate teaching modules
–Beware the hidden curriculum!!
• A few thoughts from the literature
(and my experience).
Concept Maps
Guerrero, Acad Med 2001;76:385
Torre et al., Am J Med 2006;119:903
• Graphic devices to
represent
relationships
between multiple
concepts
• Reinforce
mechanistic
thinking
• Make links explicit
Higher Order Concepts
Auclair F, BMC Medical Education 2007;7:16
• 32 third year students given complex
CPC case (endocarditis) to analyze
– 12/32 made correct dx
– Diagnostic accuracy  use of higher
order concepts. Students who missed
dx reported factual observations
• 19/25 students: given problem
formulation (i.e, concept links) made dx
• Problem not knowledge but moving
from fact to concept
Case Conference
Traditional
• 65 year old homeless
man back pain
• Hep C, spinal
lymphoma
• Later abn CXRMAC
• Discuss: tests, meds,
each disease in
isolation
Case Conference
Traditional
• 65 year old
homeless man
back pain
• Hep C, spinal
lymphoma
• Later abn
CXRMAC
• Discuss: tests,
meds, each
disease in isolation
Critical thinking
• 65 year old
homeless man
back pain
• Hep C, spinal
lymphoma
• Unifying mechs?
• Abn CXRMAC
• Discuss: make links
-immune
problemHIV
Model the Process
• Think out loud
• Discourage quick jumps to the dx
• Force the student to assess her
own thought process
• Give frequent feedback
• Test them on the process as well as
the content
Final Thoughts…
• There is more to be done to
understand the elements of critical
thinking.
• If we are serious about this, we
need to explicitly teach the process.
• Critical thinking and clinical
reasoning (as presently defined)
are not the same.
• Faculty development will be key.