1. TDG Report Illness scripts for improving clinical reasoning Anna Lee, Tony Gin, Charles Gomersall, Warwick Ngan Kee, Gavin Joynt, Anthony Ho, Juliana Chan, Lex Vlantis, James Griffith, William Wong, Coleman Fung

2. Clinical reasoning Involves solving medical problems in order to make decisions about a patient’s diagnosis and management Groves 2002

3. Key elements of the clinical diagnostic process Patient’s story Data acquisition Accurate “problem representation” Generation of hypothesis Search for and selection of illness script Diagnosis Knowledge Context Experience Bowen JL. NEJM 2006;355:2219

4. Development of Medical Expertise and clinical reasoning Driving a car = “This is the steering wheel and it………This is the brake pedal……..This is a roundabout, and at roundabouts you have to…….” Stage 1. Development of elaborate causal networks Learned during basic science years Recall facts or explain causal models of disease processes Schmidt et al. Acad Med 1990;65:611-21

5. Stage 2. Compilation of abridged networks Starts when exposed to real patients Knowledge gets compiled (rewritten, automated) Schmidt et al. Acad Med 1990;65:611-21 “Diagnosing a first clinical case requires quite a lot of mental effort and involves extensive reasoning based on the elaborate causal networks available to the student, but when he sees his second or third similar case, shortcuts will emerge. He will no longer have to activate all possibly relevant knowledge in order to understand what is going on in his patient; only knowledge pertinent to understanding the case will be activated“ Remember the first time you got in a car and drove?

6. Stage 3. Emergence of Illness scripts Based on repeated experience with patients Illness scripts are sufficient to diagnose and treat diseases Schmidt et al. Acad Med 1990;65:611-21 OK, you passed the driving test. Are you likely to be over confident? Can you assess risks quickly and accurately?

7. Illness scripts Enabling Conditions Eg. Being male, older, smoking Consequences Eg. Profuse sweating, SOB, severe and radiating chest pain Fault Eg. Myocardial infarction Van Schaik et al. J Exp Psychol 2005;11:187-99

8. Stage 4. Storing patient encounters as instance scripts Based on long experience Physician remembers many individual patients but each has a different variant of the disease New (or newly sick) patients are recognized as “similar to Patient X” treated as Patient X was treated Schmidt et al. Acad Med 1990;65:611-21 Now you’ve been driving for years. Are you sure you are up to date with the highway code? And technically, are you sure you have picked up all good habits (shortcuts), and no bad habits?

9. Project objectives To develop and implement a teaching module to improve 4 th year medical students’ clinical reasoning skills To assess students’ level of clinical reasoning skills

10. Teaching intervention Rotation to 4 th year Family Medicine module Short lecture on clinical reasoning and illness script theory (0.5h) Small group work on “problem representation” (1.5h) Individual guided computer work using clinical reasoning scenarios (1.5h)

11. Example of clinical reasoning problem Pull down menus

12. Key elements of the clinical diagnostic process Patient’s story Data acquisition Accurate “problem representation” Generation of hypothesis Search for and selection of illness script Diagnosis Knowledge Context Experience Bowen JL. NEJM 2006;355:2219

13. Assessment of clinical reasoning (1) Diagnostic Thinking Inventory Flexibility in thinking Structure of knowledge in memory CUHK teachers (n=7) Flexibility in thinking (77%) Structure of knowledge in memory (78%) Bordage et al. Med Educ 1990;24:413-25

14. Assessment of clinical reasoning (2) Clinical reasoning problems Different set of scenarios Students type their answers/cut and past key features from scenarios (spell-check features) Scores given to correct diagnoses and key features

16. Assessing students’ learning outcome StudentsBegin rotationTeaching packageEnd of rotation InterventionDiagnostic Thinking Inventory (25 min online) Clinical reasoningDiagnostic Thinking Inventory + clinical reasoning scenarios on web (2 hours) ControlDiagnostic Thinking Inventory (25 min online) Self-directed learning Diagnostic Thinking Inventory + clinical reasoning scenarios on web (2 hours)