Diagnostic Reasoning “DR” Toolbox
Heather Hofmann, MD Department of Medicine
2017-18
for Hospitalist Faculty
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Goal Increase faculty familiarity with diagnostic reasoning principles and tools so as to
improve its teaching.
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Three Parts:
I: Introduction to Diagnostic Reasoning II: DR Toolbox III: Structured Reflection Exercise (SRE)
Part I: Introduction to Diagnostic Reasoning
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Learning Objectives
- Understand the “what” and “why” of Diagnostic Reasoning
- Recognize dual-process theory’s role in “how” we reason
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What is Diagnostic Reasoning?
- Clinical reasoning - The process of thinking and decision making, consciously & unconsciously
guide practice actions
chest pain STEMI in proximal LAD
abdominal pain acute appendicitis
25yo female G1P0, 2m gestation returns from Rio.
- Diagnostic reasoning: - The process of collecting & analyzing information
establish a diagnosis
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Why teach diagnostic reasoning?
- Incorrect diagnoses are often at the root of medical errors
- DR is a means to apply basic science to clinical problems
- Central to being a physician
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Patient’s perspective
What’s wrong with me?
Is it bad?
What can we do about it?
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Why now?
Never too early for practice
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From Novice to Expert
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How do we reason?
Information processing theory
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How do we reason?
Information processing theory: Dual process theory.
Analytical Conscious
Type/System 2
Slow
Effortful
Deliberative
Logical
Requires attention, self-control, time.
Hypothesis-driven, Bayesian (probability)
Non-analytical Unconscious
Type/System 1
Fast
Automatic
Involuntary
Emotional
Executes skilled response and
generates “intuition” with minimal effort
Pattern recognition (illness scripts)
Heuristics
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From Novice to Expert
Analytical
Non-Analytical
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Can you learn/improve diagnostic reasoning?
Nonanalytic diagnostic reasoning
Analytic diagnostic reasoning
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Caveats
Diagnostic reasoning is a skill that improves with practice
It is highly individualized—both by the physician and for each given patient case
An ever growing fund of knowledge is critical
Part II: Diagnostic Reasoning Toolbox
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Learning Objectives
- Review principles for teaching DR to students
- Define key terms in teaching DR
- Review tips for leading teaching session
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Principles for teaching DR to clinical students
1. Student should be familiar with typical presentations of common diseases. Start to incorporate atypical presentations of common diseases, gradually increasing complexity.
2. Explicitly discuss clinical reasoning processes during case discussions.
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Definitions
Illness script
Scheme induction
Problem lists
Problem representation/summary statement
Framework
Differential diagnosis
Scaffolds
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Definitions
Illness script
Scheme induction
Problem lists
Problem representation/summary statement
Framework
Differential diagnosis
Scaffolds
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Illness scripts
Mental constructs of disease manifestations.
“The internal rolodex of diseases.”
How we store disease prototype in order to then use it for pattern recognition.
Non-analytical Unconscious
Type/System 1
Fast
Automatic
Involuntary
Emotional
Executes skilled response and
generates “intuition” with minimal effort
Pattern recognition (illness scripts),
Heuristics
Odds are you have a lot of these, but students
have few, immature ones
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Illness scripts Non-analytical Unconscious
Type/System 1
Fast
Automatic
Involuntary
Emotional
Executes skilled response and
generates “intuition” with minimal effort
Pattern recognition (illness scripts),
Heuristics
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Definitions
Illness script
Scheme induction
Problem lists
Problem representation/summary statement
Framework
Differential diagnosis
Scaffolds
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Scheme induction
A systematic application of rules to narrow the differential diagnosis of a symptom, sign, or lab.
Analytical Conscious
Type/System 2
Slow
Effortful
Deliberative
Logical
Requires attention, self-control, time.
Hypothesis-driven, Bayesian (probability), Worst-case scenario,
EBM
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Definitions
Illness script
Scheme induction
Problem lists
Problem representation/summary statement
Framework
Differential diagnosis
Scaffolds
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Problem lists
Lawrence Weed
A mechanism to summarize the state of a patient’s health in written documentation.
Many uses.
They can evolve within a history and across encounters.
Warning: Don’t lose the big picture.
Features of Effective Problem Lists
Use precise language
Update and modify over time
Prioritize
Make associations between problems
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Definitions
Illness script
Scheme induction
Problem lists
Problem representation/summary statement
Framework
Differential diagnosis
Scaffolds
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Problem representation/summary statement/one-liner/Impression
The description of the patient’s presentation.
Example 1: Mr. Smith is a 64-year-old man with the ischemic cardiomyopathy who presents with a
two day history of gradual onset, worsening dyspnea on exertion and findings of hypoxia, bilateral
crackles, elevated JVP, and lower extremity edema.
Example 2: Ms. Jones is a 33-year-old woman with a history of heavy alcohol use and NSAID use
who presents with two days of severe, burning, and midepigastric abdominal pain and acute
melena. Her examination is notable for hemodynamic instability, soft, nontender abdomen with
normal bowel sounds, no organomegaly or jaundice, normal rectal exam, but positive stool heme
testing.
3 Critical Components of Problem Representation
Clinical context
Temporal pattern
Key clinical symptoms and exam findings that relate to presenting symptoms.
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Problem representation/summary statement/one-liner vs. illness script
Very similar! And use patients to build illness scripts!
Patient-specific vs. disease-specific.
Both benefit from semantic qualifiers.
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Definitions
Illness script
Scheme induction
Problem lists
Problem representation/summary statement
Framework
Differential diagnosis
Scaffolds
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Framework
A means of building differential diagnoses.
NOT patient-specific.
Examples: Worst-First Approach
Mnemonics (e.g., VINDICATE)
Organ System- or Anatomic-based
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Differential diagnosis
Potential etiologies of a given patient problem.
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Worst-First Framework
• Ask yourself: Is this life-threatening? Does this patient need to be in an ED?
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• Chest pain: ACS vs. Aortic Dissection vs. PE vs. esophageal rupture vs. other non-life threatening
• Dyspnea: MI vs. CHF vs. COPD vs. asthma vs. PTX vs. PE
• Abdominal pain: pancreatitis vs. perforated viscus vs. Mallory Weiss tear vs. cholangitis vs. GERD
• Hematochezia: variceal bleed vs. diverticulosis vs. hemorrhoids vs. colon cancer vs. brisk upper GI bleed
Worst-First Examples
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VINDICATE (mnemonic Framework)
V Vascular
I Infectious
N Neoplastic
D Drugs
I Inflammatory, Idiopathic
C Congenital
A Autoimmune/Allergic
T Traumatic (including psychological trauma)
E Endocrine
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Vascular • Stroke (ischemic/ hemorrhagic) • TIA • HTN encephalopathy
Infectious • Encephalitis • Meningitis • Sepsis
Neoplastic • 1’ or metastatic tumor
Drugs/Toxins • Overdose/ Withdrawal
Inflammatory • SIRS, vasculitis, pancreatitis,
endocarditis
Congenital • Epilepsy
Autoimmune • Seizure in lupus patient
Trauma • Subdural bleed
Endocrine • Hypo/hyperglycemia • Hypo/hypernatremia • Uremia, ammonia • Hyper/hypothyroid
VINDICATE for CC: Altered Mental Status
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Organ System or Anatomic-Based Approach
• Define complaint anatomically
• If systemic disease, identify specific anatomic involvement
• Be thorough
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Anatomic Approach to Chest Pain
Skin?
Muscle?
Ribs?
Pericardium?
Myocardium?
Coronary vessels?
Pleura?
Lung parenchyma?
Pulmonary vessels?
Esophagus?
By Henry Vandyke Carter - Henry Gray
(1918) Anatomy of the Human Body (See
"Book" section below)Bartleby.com:
Gray's Anatomy, Plate 492, Public
Domain,
https://commons.wikimedia.org/w/index.ph
p?curid=545522
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Definitions
Illness script
Scheme induction
Problem lists
Problem representation/summary statement
Framework
Differential diagnosis
Scaffolds
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Scaffolds: how to develop students’ reasoning skills.
OLD CARTS
Schema
Problem Lists
SRE
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Definitions
Illness script
Scheme induction
Problem lists
Problem representation/summary statement
Framework
Differential diagnosis
Scaffolds
Part III: Structured Reflection Exercise (SRE)
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Learning Objectives
- Review the evidence-based method for assessing diagnostic reasoning
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ACS
CAD risk factors
30 years old
Summary Increase faculty familiarity with diagnostic reasoning principles and tools so as to
improve its teaching.
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Three Parts:
I: Introduction to Diagnostic Reasoning II: DR Toolbox III: SRE
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References
Gordon, D., & Guth, T. (2013). Clinical Reasoning in Medical Students : Retrieved from http://www.cordem.org/files/DOCUMENTLIBRARY/2013 AA/2013 Day Two/Deliberate Metacognition.pdf
Kearney-Strouse, J. (2015). Clinical reasoning now a ‘foundational basic science’ in medical education. ACP Hospitalist. https://acphospitalist.org/archives/2015/11/teaching-clinical-reasoning.htm
Khullar, D., Jha, A. K., & Jena, A. B. (2015). Reducing Diagnostic Errors — Why Now? New England Journal of Medicine, 363(1), 150923140040009. http://doi.org/10.1056/NEJMp1508044
Levin M, Cennimo D, Chen S, Lamba S. Teaching clinical reasoning to medical students: a case-based illness script worksheet approach. MedEdPORTAL Publications. 2016;12:10445.
Modi, J. N., Gupta, P., & Singh, T. (2015). Teaching and Assessing Clinical Reasoning Skills. Indian Pediatrics, 52(9), 787–794. http://doi.org/10.1007/s13312-015-0718-7
Outpatient Diagnostic Errors Affect 1 in 20 U.S. Adults, AHRQ Study Finds. Content last reviewed April 2014. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/news/newsroom/press-releases/2014/diagnostic_errors.html
Toy, E., & Patlan, J. (2012). Case Files Internal Medicine.
Trowbridge, R., Rencic, J., & Durning, S. J. (Eds.). (2015). Teaching Clinical Reasoning. ACP.
Wolpaw, T. M., Papp, D. R., & Klara, K. (2016). Academic Medicine : SNAPPS : A Learner ‐ centered Model for Outpatient Education, 78(9), 1–7.