Theoretical aspects of clinical reasoning and decision-making And their application to clinical teaching

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1 Theoretical aspects of clinical reasoning and decision-making And their application to clinical teaching Kevin W. Eva Program for Educational Research and Development Department of Clinical Epidemiology and Biostatistics McMaster University

2 A 43-year old woman is brought to the Emergency Room by her husband at 2:00 in the morning because of acute shortness of breath. The dyspnea occurred suddenly at 11:00 pm and had awoken the patient from sleep. She felt nauseated and vomited a small amount of bile. She complained of retrosternalchest pain that was worse on deep breathing. For several days she had coughed up small amounts of blood. For four days she had felt unwell and had a sore throat and sinus congestion that resolved. She complained of fever and chills on several occasions in the past few days. The previous night she awoke with chest tightness, but this settled after a short while. There was a history of bronchitis in the past.

3 What is the most likely diagnosis? Answering this question requires Careful observation Elicitation of appropriate history Accurate physical maneuvers Generation of hypotheses Appreciation of the relation b/w diagnoses and data Attempts to confirm/refute hypotheses through diagnostic testing

4 The Plan A brief history of the study of expertise in medicine Current exploration of the coordination between analytic and non-analytic reasoning processes Implications for undergraduate and continuing education

5 The early days of expertise The 60s and 70s Expertise characterized as the development of generic problem solving skills The goal of PBL: Create good problem solvers Evaluation tools (e.g., PMPs) - focused on objectively measuring problem solving tendencies (see Norman, 2005)

6 The fall of an empire 1. Process differences hard to come by E.g., 5 to 7 hypotheses typically generated early in the course of a case by experts and novices (Barrows, et al., 1982; Neufeld, et al., 1981) 2. Context specificity omnipresent Performance across problems unrelated (Elstein, et al., 1978; Eva, 2003)

7 A paradigm shift The essence of intelligence is less a matter of reasoning and more a matter of knowing a lot about the world (Simon, 1969)

8 An impact felt far and wide Problem-based learning curricula Forced to re-orient to account for the need to master specific knowledge Evaluation Lack of generalizability created need to frequently sample ability (e.g., OSCEs) Views of expertise Organization of knowledge became central focus

9 Controversy in Med Ed Non-analytic processes Analytic processes

10 Traditional models of reasoning Tend to be analytic in nature Advocate careful, controlled consideration of features Treat features as plainly evident Treat expertise as development and elaboration of rules Treat reasoning as an application of these rules E.g., Bayes theorem: Pre-test odds x Likelihood ratio = Post-test odds

11 A 43-year old woman is brought to the Emergency Room by her husband at 2:00 in the morning because of acute shortness of breath. The dyspnea occurred suddenly at 11:00 pm and had awoken the patient from sleep. She felt nauseated and vomited a small amount of bile. She complained of retrosternalchest pain that was worse on deep breathing. For several days she had coughed up small amounts of blood. For four days she had felt unwell and had a sore throat and sinus congestion that resolved. She complained of fever and chills on several occasions in the past few days. The previous night she awoke with chest tightness, but this settled after a short while. There was a history of bronchitis in the past.

12 A 43-year old woman is brought to the Emergency Room by her husband at 2:00 in the morning because of acute shortness of breath. The dyspnea occurred suddenly at 11:00 pm and had awoken the patient from sleep. She felt nauseated and vomited a small amount of bile. She complained of retrosternalchest pain that was worse on deep breathing. For several days she had coughed up small amounts of blood. For four days she had felt unwell and had a sore throat and sinus congestion that resolved. She complained of fever and chills on several occasions in the past few days. The previous night she awoke with chest tightness, but this settled after a short while. There was a history of bronchitis in the past.

13 A 43-year old woman is brought to the Emergency Room by her husband at 2:00 in the morning because of acute shortness of breath. The dyspnea occurred suddenly at 11:00 pm and had awoken the patient from sleep. She felt nauseated and vomited a small amount of bile. She complained of retrosternalchest pain that was worse on deep breathing. For several days she had coughed up small amounts of blood. For four days she had felt unwell and had a sore throat and sinus congestion that resolved. She complained of fever and chills on several occasions in the past few days. The previous night she awoke with chest tightness, but this settled after a short while. There was a history of bronchitis in the past.

14 A 43-year old woman is brought to the Emergency Room by her husband at 2:00 in the morning because of acute shortness of breath. The dyspnea occurred suddenly at 11:00 pm and had awoken the patient from sleep. She felt nauseated and vomited a small amount of bile. She complained of retrosternalchest pain that was worse on deep breathing. For several days she had coughed up small amounts of blood. For four days she had felt unwell and had a sore throat and sinus congestion that resolved. She complained of fever and chills on several occasions in the past few days. The previous night she awoke with chest tightness, but this settled after a short while. There was a history of bronchitis in the past.

15 Teaching analytic processes Expertise = Development and elaboration of rules Most textbooks set up this way Education = Facilitating internalization of rules E.g., Elieson & Papa (1994) -provided students with probability charts

16 The lesson Be objective Don t jump the gun Collect all of the available information before making a decision These instructions are too facile!

17 A 43-year old woman is brought to the Emergency Room by her husband at 2:00 in the morning because of acute shortness of breath. The dyspnea occurred suddenly at 11:00 pm and had awoken the patient from sleep. She felt nauseated and vomited a small amount of bile. She complained of retrosternalchest pain that was worse on deep breathing. For several days she had coughed up small amounts of blood. For four days she had felt unwell and had a sore throat and sinus congestion that resolved. She complained of fever and chills on several occasions in the past few days. The previous night she awoke with chest tightness, but this settled after a short while. There was a history of bronchitis in the past.

18 Hatala, et al. (1999) ECG Interpretation by students / residents Practice: Middle aged banker or elderly woman with CP (Anterior MI) Test: Middle aged banker (Left Bundle Branch Block)

19 Hatala, et al. (1999)

20 Non-analytic processes (Norman and Brooks, 1997) Pattern recognition Effortless, automatic, unconscious Memories consist of stores of prior experiences Problem solution presents all at once (Gestalt) thanks to availability of prior instances

21 One becomes an expert by making routine many aspects of a problem which require creative problem solving by a novice (Anderson, 1980)

22 A combined model (see Eva, 2005) Success as a diagnostician is characterized by flexibility Many sources of information are available to act independently and be coordinated during diagnosis (Custers, Regehr, and Norman, 1996) The good are not good at everything and the poor are not poor at everything (Levy and Hinchley, 1990)

23 Breaking the continuum Non-analytic processes Combined Analytic processes

24 Issue #1 Description of reasoning processes is interesting, but how does it help educationally? Pattern recognition should not be advocated among medical students for fear of potentially grim consequences (Coderre, et al., 2003)

25 Study #1 Method Trained undergraduate Psychology students ECG diagnosis (11 categories) Learning phase: Present rules Present pair of examples Identify features in second pair of examples

26 Study #1 Method (cont d) Practice (10 ECGs presented with feedback) and Test (20 ECGs, half old, half new) phases: Feature first: List all features, then assign diagnosis First impression: Trust sense of familiarity Combined: Trust familiarity, but don t jump the gun

27 Study #1 Diagnostic Accuracy Feature First Old ECGs First Impression Combined New ECGs Ark, Brooks, and Eva (2006)

28 Study #1 Feature calls Hits Indicative Hits Not Indicative False Alarms Analytic Non-analytic Combined

29 Issue #2 Did we improve performance by providing combined instruction or did we harm performance by providing isolated diagnostic strategies? In other words, should we just leave students well enough alone?

30 Study #2 Similar procedure: 3 phase study with undergrads Combined Instruction: Trust familiarity, but don t jump the gun No Instruction: Diagnose each ECG in whatever way seems natural Contrastive Instruction: Asked to explicitly compare/contrast each ECG to Normal wave form and to a confusable differential Non-Contrastive Instruction: Standard (sequential) teaching technique

31 Study #2 Immediat Delayed Diagnostic Accuracy Contrastive Non-contrast Diagnostic Accuracy Contrastive Non-contrast CombinedSpontane CombinedSpontane Ark, Brooks, and Eva (2007)

32 Issue #3 What happens when things get difficult? Diagnosticians can be biased by information presented at the: Feature level: By prompting them to focus attention on specific features Categorical level: By prompting them to consider specific diagnoses

33 Study #3 Similar procedure: 3 phase study with undergrads Combined Instruction: Trust familiarity, but don t jump the gun No Instruction: Diagnose each ECG in whatever way seems natural Feature level interference: Asked to explicitly consider the presence of a feature that was indicative of an incorrect diagnosis No interference: No specific prompts provided

34 Study #3 Diagnostic Accuracy Combined No Interference Spontaneous Interference Eva, Hatala, LeBlanc, and Brooks (2007)

35 Study #4 Similar procedure: 3 phase study with undergrads Combined Instruction: Trust familiarity, but don t jump the gun No Instruction: Diagnose each ECG in whatever way seems natural Category level interference: Told a colleague had suggested a particular diagnosis (either correct or incorrect) No interference: No specific prompts provided

36 Study #4 Diagnostic Accuracy Combined Spontaneous Bias Incorrect Neutral Bias Correct Eva, Hatala, LeBlanc, and Brooks (2007)

37 Discussion Errors arise from too little control and too much control Results reveal the benefit of explicit instructions to take advantage of the strengths both classes of reasoning strategies offer Not a universal method per se, but rather, an indication of the value of flexibility

38 The union of processes Patient presents Case representation Hypotheses tested Non-analytic processes Additive Analytic processes (see Eva, 2005)

39 Finding a balance Expertise is a flexible entity -Competent clinicians can compensate for casespecific weaknesses While it might seem obvious that students would use multiple strategies spontaneously, these results reveal the benefit of explicit instructions At the same time, they also suggest that educators should not shy away from noting the value of nonanalytic processes

40 Conclusions Problem-solving is not a generic skill one can possess The most experienced practitioners rarely engage in problem solving No individual should get locked into one particular mode of problem solving There is guidance in the literature regarding how the likelihood of problem-solving can be maximized

41 An expert is a person who has made all the mistakes that can be made in a very narrow field (Niels Bohr)

42 Thanks

Clinical teachers differ from clinicians in a fundamental way.

review article medical Education Malcolm Cox, M.D., and David M. Irby, Ph.D., Editors Educational Strategies to Promote Clinical Diagnostic Reasoning Judith L. Bowen, M.D. Clinical teachers differ from