Post on 05-Jan-2016
Individual Errors and Individual Errors and HeuristicsHeuristicsEthan Cumbler M.D.Ethan Cumbler M.D.
Assistant Professor of MedicineHospitalist Section
University of Colorado Hospital20072007
THE UNSINKABLE TITANIC
The Psychology of The Psychology of Medical ErrorMedical Error
In the first module In the first module we discussed we discussed systems issues in systems issues in relation to relation to medical error.medical error.
In this module we will discuss individual errors.In this module we will discuss individual errors.
Medical CognitionMedical Cognition
Hypothesis generation (data to Hypothesis generation (data to hypothesis)hypothesis)
Followed byFollowed by Hypothesis evaluationHypothesis evaluation
Deductive Deductive reasoningreasoning
Drawing conclusions based on a set of Drawing conclusions based on a set of assumptionsassumptions
All lizards are reptilesAll lizards are reptiles No cats are reptilesNo cats are reptiles Therefore no cats are lizardsTherefore no cats are lizards Deductive reasoning breaks down when Deductive reasoning breaks down when
the truth of a premise is unclear or the truth of a premise is unclear or when a premise is false.when a premise is false.
Inductive Inductive reasoningreasoning
Takes us from the observed to the Takes us from the observed to the unobserved.unobserved.
Since the sun has risen every day we Since the sun has risen every day we induce that it will likely rise again induce that it will likely rise again tomorrow.tomorrow.
Leads to the black swan fallacy of Leads to the black swan fallacy of inductive reasoning. Just because every inductive reasoning. Just because every swan we have ever seen is white does not swan we have ever seen is white does not mean that there can not be a black swan.mean that there can not be a black swan.
Abductive reasoningAbductive reasoning
Combines deducuctive and Combines deducuctive and inductive reasoning in medical inductive reasoning in medical thinkingthinking
Uses deductive thinking to Uses deductive thinking to generate hypotheses then generate hypotheses then inductive reasoning to test and inductive reasoning to test and potentially rule out each one.potentially rule out each one.
Iterative Hypothesis TestingIterative Hypothesis Testing
These descriptions of decision making These descriptions of decision making likely do not reflect the real world of likely do not reflect the real world of medical cognition which involves both medical cognition which involves both explicit conscious decision making but explicit conscious decision making but also “fuzzy logic” in a highly complex also “fuzzy logic” in a highly complex milieumilieu
Perhaps this is why the hospital is Perhaps this is why the hospital is described as a “natural laboratory of described as a “natural laboratory of error”error”
Types of ErrorsTypes of Errors
Knowledge- mistake from inadequate or Knowledge- mistake from inadequate or incomplete information. Least commonincomplete information. Least common
Rule based- the incorrect application of Rule based- the incorrect application of the information ie patient with chest pain the information ie patient with chest pain due to MI thought to be costochondritis. due to MI thought to be costochondritis. We think of this as a “lapse of judgement”We think of this as a “lapse of judgement”
Skill based- performance error ie intended Skill based- performance error ie intended to correct potassium but forgot. Most to correct potassium but forgot. Most common. We think of this as a “slip”common. We think of this as a “slip”
Types of ErrorsTypes of Errors
Rule-based judgment errors may Rule-based judgment errors may seem like unpredictable events seem like unpredictable events but cognitive dispositions referred but cognitive dispositions referred to as heuristics lead to to as heuristics lead to predisposition to judgment error predisposition to judgment error under predictable circumstances. under predictable circumstances.
HueristicHueristic
Involving or serving as an aid to learning, Involving or serving as an aid to learning, discovery, or problem-solving by discovery, or problem-solving by exploratory techniques that use self exploratory techniques that use self educationeducation
Comes from the Greek term Comes from the Greek term heuriskeinheuriskein for for discoverydiscovery
In medical decision making we frequently In medical decision making we frequently think of these as mental shortcuts which think of these as mental shortcuts which allow physicians to move forward with the allow physicians to move forward with the thousands of decisions which are needed thousands of decisions which are needed each day without painful baysean analysis each day without painful baysean analysis for each one.for each one.
Heuristic failuresHeuristic failures
Goal of the physician is to recognize that Goal of the physician is to recognize that while heuristics are useful, they also can while heuristics are useful, they also can set you up for errorsset you up for errors
Sometimes this is referred to as Sometimes this is referred to as “Cognitive dispositions to respond”“Cognitive dispositions to respond”
Understanding how the mental shortcuts Understanding how the mental shortcuts we take can lead to predictable mistakes we take can lead to predictable mistakes takes some of the apparent randomness takes some of the apparent randomness out of medical errorout of medical error
Heuristic FailuresHeuristic Failures
Think of this as the use of “cognitive Think of this as the use of “cognitive forcing strategies” to avoid errorforcing strategies” to avoid error
Similar concept when we recommend a Similar concept when we recommend a CT scan prior to LP for a patient who is CT scan prior to LP for a patient who is obtunded and febrile. Recognizing the obtunded and febrile. Recognizing the potential for inadequate neurologic potential for inadequate neurologic exam for focality we routinely perform exam for focality we routinely perform the scan. Think how different this is the scan. Think how different this is then simply recommending the then simply recommending the physician “try harder to get a good physician “try harder to get a good exam”exam”
Selected CDRsSelected CDRs
Anchoring: Anchoring: The tendency to lock on to the features of the early The tendency to lock on to the features of the early
presentation and not adjust the initial impression in presentation and not adjust the initial impression in light of later informationlight of later information
This can be further exacerbated by the confirmation This can be further exacerbated by the confirmation bias and the sunk cost biasbias and the sunk cost bias
Confirmation Bias:Confirmation Bias: The tendency to seek confirming evidence to support The tendency to seek confirming evidence to support
a diagnosis rather than look for elements which would a diagnosis rather than look for elements which would refute the hypothesisrefute the hypothesis
““Sunk Cost Bias” in which the clinician becomes Sunk Cost Bias” in which the clinician becomes unwilling to abandon a diagnosis into which unwilling to abandon a diagnosis into which considerable effort has been expendedconsiderable effort has been expended
Selected CDRsSelected CDRs
Availability Bias:Availability Bias: Disposition to judge a diagnosis as Disposition to judge a diagnosis as
being more likely if you have seen it being more likely if you have seen it more recently.more recently.
Are there more words which start with Are there more words which start with the letter R or which have the letter R the letter R or which have the letter R in the 3in the 3rdrd position? position?
Which kills more people. Homicide or Which kills more people. Homicide or gastric cancer?gastric cancer?
Selected CDRsSelected CDRs
Commission Bias:Commission Bias: Tendency to prefer action to inactionTendency to prefer action to inaction Omission Bias:Omission Bias: Tendency towards inaction “first do no Tendency towards inaction “first do no
harm” harm” Typically Omission is more common Typically Omission is more common
than Commission. The most common than Commission. The most common cause of malpractice in the ER is failure cause of malpractice in the ER is failure to diagnoseto diagnose
Selected CDRsSelected CDRs
Diagnosis Momentum:Diagnosis Momentum: The tendency for a diagnosis to The tendency for a diagnosis to
become “stickier” with repetition. become “stickier” with repetition. Think of this as a potential pitfall Think of this as a potential pitfall
of the electronic medical record of the electronic medical record where an incorrect allergy can be where an incorrect allergy can be repeated in subsequent notes repeated in subsequent notes gaining veracity with each note gaining veracity with each note which sites it.which sites it.
Selected CDRsSelected CDRs
Framing Effect: How the diagnostician Framing Effect: How the diagnostician sees things is influenced by the way it sees things is influenced by the way it is presentedis presented
““patients with dementia who require patients with dementia who require CPR have a 95% chance of dying prior CPR have a 95% chance of dying prior to discharge” versus “patients with to discharge” versus “patients with dementia who require CPR have a 5% dementia who require CPR have a 5% chance of surviving to discharge”chance of surviving to discharge”
Selected CDRsSelected CDRs
Fundamental Attribution Error:Fundamental Attribution Error: The tendency to give greater weight The tendency to give greater weight
to the patients characteristics then to the patients characteristics then to other elements of the situationto other elements of the situation
Think about a patient with Think about a patient with schizophrenia who is agitated and it schizophrenia who is agitated and it is attributed to psychosis rather is attributed to psychosis rather than a foley with bulb inflated in the than a foley with bulb inflated in the urethraurethra
Selected CDRsSelected CDRs
Gambler’s Fallacy:Gambler’s Fallacy: The incorrect belief that the next item The incorrect belief that the next item
in a sequence of events will be in a sequence of events will be influenced by the results of the influenced by the results of the preceding events even though they preceding events even though they are independent. are independent.
If 10 flips of the coin turn up heads If 10 flips of the coin turn up heads then surely the next one will be then surely the next one will be tails…… right?tails…… right?
Selected CDRsSelected CDRs
Multiple Alternatives Bias:Multiple Alternatives Bias: The tendency when faced with The tendency when faced with
multiple potential possibilities to multiple potential possibilities to try to simplify it to a less complex try to simplify it to a less complex list by ignoring some options.list by ignoring some options.
Also the tendency to be paralyzed Also the tendency to be paralyzed by multiplicity of options. by multiplicity of options.
Selected CDRsSelected CDRs
Order Effects:Order Effects: The tendency to pay more The tendency to pay more
attention to the first part of a set attention to the first part of a set of information (primacy effect) or of information (primacy effect) or the last part (recency effect)the last part (recency effect)
Leads to error if the middle bit is Leads to error if the middle bit is just as importantjust as important
Selected CDRsSelected CDRs
Triage Cueing:Triage Cueing: The initial selection of location or The initial selection of location or
specialist has disproportionate specialist has disproportionate influence on subsequent care.influence on subsequent care.
““geography is destiny”geography is destiny”
Selected CDRsSelected CDRs
Premature Closure:Premature Closure: The tendency to accept a decision The tendency to accept a decision
before it is completely verifiedbefore it is completely verified ““When the diagnosis is made….the When the diagnosis is made….the
thinking stops”thinking stops” Satisfied Search, the bane of the Satisfied Search, the bane of the
radiologist, is a variant of this CDRradiologist, is a variant of this CDR
Other CDRsOther CDRs
Base-rate neglect: Base-rate neglect: incorrect assessment of the incorrect assessment of the prevalence of a diseaseprevalence of a disease
Feedback sanction: Feedback sanction: a system issue where errors a system issue where errors can be repeated if the error has no immediate can be repeated if the error has no immediate consequenceconsequence
Gender bias: Gender bias: Form of Ascertainment BiasForm of Ascertainment Bias
Hindsight bias: Hindsight bias: Knowledge of outcome influences Knowledge of outcome influences perception of past eventsperception of past events
Outcome bias: Outcome bias: A form of Value Bias where the A form of Value Bias where the physician favors the diagnosis they hope for rather than physician favors the diagnosis they hope for rather than what is most likelywhat is most likely
Other CDRsOther CDRs
Overconfidence Bias: Overconfidence Bias: A universal tendency to A universal tendency to believe we know more than we dobelieve we know more than we do
Unpacking principal: Unpacking principal: the more specific a the more specific a description of an illness, the more likely it is judged to description of an illness, the more likely it is judged to existexist
Vertical line failure: Vertical line failure: overly limited “silo thinking”overly limited “silo thinking” Visceral bias: Visceral bias: emotional arousal leads to poor emotional arousal leads to poor
decision makingdecision making The Aggregate Fallacy: The Aggregate Fallacy: The belief that the The belief that the
individual patient is atypical from that of aggregate data individual patient is atypical from that of aggregate data (such as those used to develop clinical practice (such as those used to develop clinical practice guidelines)guidelines)
Other CDRsOther CDRs
Representativeness Restraint:Representativeness Restraint:The The diagnostician looks for typical presentations. “looks diagnostician looks for typical presentations. “looks like a duck, quacks like a duck, probably a duck”. Will like a duck, quacks like a duck, probably a duck”. Will lead you to miss an atypical presentation. Sometimes lead you to miss an atypical presentation. Sometimes called “Suttons Slip” after the bank robber who called “Suttons Slip” after the bank robber who famously said he robs banks because “that’s where famously said he robs banks because “that’s where the money is”the money is”
Ascertainment Bias: Ascertainment Bias: When prior When prior expectations shape thinking. Example would be a expectations shape thinking. Example would be a racial or gender stereotyperacial or gender stereotype
Cognitive De-biasing Cognitive De-biasing strategiesstrategies
Awareness of types of CDRsAwareness of types of CDRs Forced consideration of alternative Forced consideration of alternative
possibilities such as differential diagnosis on possibilities such as differential diagnosis on initial presentation and with interval initial presentation and with interval reevaluations.reevaluations.
Metacognition which refers to a reflective Metacognition which refers to a reflective consideration of the logical processconsideration of the logical process
Minimize time pressureMinimize time pressure FeedbackFeedback SimulationsSimulations Cognitive aids (such as algorithms)Cognitive aids (such as algorithms)
Putting Theory Into Putting Theory Into PracticePractice Begin Case Study in Heuristics Begin Case Study in Heuristics
ErrorError
ReferencesReferences
1.1. Croskerry P. The Importance of Cognitive Errors in Croskerry P. The Importance of Cognitive Errors in Diagnosis and Stratagies to Minimize Them. Acad Diagnosis and Stratagies to Minimize Them. Acad Med 2003;78:775-780Med 2003;78:775-780
2.2. Graber M, Gordon R, Franklin N. Reducing Graber M, Gordon R, Franklin N. Reducing Diagnostic Errors in Medicine: Whats the Goal? Acad Diagnostic Errors in Medicine: Whats the Goal? Acad Med 2002;77:981-992Med 2002;77:981-992
3.3. Redelmeier DA, Ferris LE, Tu JV, Hux JE, Schull MJ. Redelmeier DA, Ferris LE, Tu JV, Hux JE, Schull MJ. Problems For Clinical Judgement: Introducing Problems For Clinical Judgement: Introducing Cognitive Psychology as One More Basic Science. Cognitive Psychology as One More Basic Science. JAMC 2001;164:358-360JAMC 2001;164:358-360
4.4. Human Error. Reason, James. Cambridge University Human Error. Reason, James. Cambridge University Press, Cambridge 1990.Press, Cambridge 1990.
5.5. How Doctors Think. Groopman, Jerome. Houghton How Doctors Think. Groopman, Jerome. Houghton Mifflin Company, New York 2007.Mifflin Company, New York 2007.
ReferencesReferences
6.6. Redelmeler DA. The Cognitive Psychology of Missed Redelmeler DA. The Cognitive Psychology of Missed Diagnoses. Ann Intern Med 2005;142:115-120Diagnoses. Ann Intern Med 2005;142:115-120