Cognitive Error The 2012 shortlist

Over-attachment to a particular diagnosis Anchoring = (The most common biases) –‘Jumping to conclusions based on first impression’ –‘Premature Closure’ Confirmation Bias = searching only for confirmatory evidence to support early conclusions –Interpretation of ambiguous evidence as supporting their existing position –greater reliance on information encountered first in a series Sunk Costs (‘Concorde fallacy’) Two specific features: -An overly optimistic probability bias -Sunk cost appears to operate chiefly in those who feel personal responsibility for the investments that are to be viewed as sunk. Colloquially known as "throwing good money after bad".

Concorde Fallacy The sunk cost fallacy, also known as the "Concorde Fallacy”, refers to the British and French governments continued funding of the joint development of the Concorde even after it became apparent that there was no longer an economic case for the aircraft. The project was regarded privately by the British government as a "commercial disaster" which should never have been started.

Failure to consider alternative Diagnoses Representativeness Restraint –Looking only for classic presentation –“Doesn’t quack so it can’t be a duck” –Common in inexperienced clinicians Sutton’s slip –Sutton’s Law - “go where the $ is.” –Going for the obvious, dismissing inconsistent data and other possibilities –E.g. Chest pain and ECG suggest AMI. Missing wide mediastinum on CXR and aortic dissection.

Error due to Inheriting Someone else’s thinking Diagnostic Momentum –Handover prone time Bandwagon effect –As more people come to believe in something, others also "jump on the bandwagon" regardless of the underlying evidence

Other Attentional Bias –We normally give increased attention or hyper- attention to both attractive and threatening materials. In cognitive psychology attentional bias refers to hyper-attention to threatening information despite the absence of evidence that the threat may be unrealistic. –suggestion a hyper-vigilant cognitive style that gives high processing priorities to threat-related stimuli, thereby promoting escalation of fear

Error in Prevalence Perception or Estimation Playing the odds Posterior Probability Error –Applying what happened previously without searching for new evidence –e.g assuming migraine when meningitis or SAH

Errors Involving Patient Characteristics or presentation Context Psych-out Error –patient’s symptoms attributed to psychiatric illness or condition (similar to attribution error) Triage cueing –Patient location affects the differential diagnosis e.g. Wait Room v Resus Yin-Yang out –“has been worked up the ying-yang” process may have evolved may be a new/different process fresh approach/unbiased thinking required Visceral bias –influence of affective sources of error on decision making; as with countertransference, negative and positive feelings toward patients may result in diagnoses being missed

Errors associated with physician affect personality or decision style Commission Bias –Inappropriate urge toward action –Common if patient colleague/ healthcare worker Overconfidence Bias Belief Bias Ego Bias Zebra Retreat –Retreat from rare diagnosis –“Nah, it can’t be.” –Especially if timely diagnosis is important

Case 1 Patient fell 15 ft from ladder onto concrete; brought by ambulance to ED without immobilization; x-rays of both ankles showed fractured right ankle (swollen and deformed); referred to ortho who put on walking cast; 6 wk later, cast removed (patient complaining of foot pain); 4 wk later, foot x-ray (ordered by another physician) revealed calcaneal fracture; orthopedic shoe ineffective; bone fusion required Analysis: considerations in fall from height—calcaneal fracture; injuries to lumbar spine; jump (suicide attempt) Errors: deficient knowledge (about falls from heights) search satisficing (ankle fracture found, no search for other injuries; 15%- 20% of traumatic injuries missed on initial examination) diagnostic anchoring (orthopaedic team fixated on ankle fracture, despite further information about foot pain) diagnosis momentum (diagnostic label of ankle fracture stuck to patient premature diagnostic closure (once diagnosis made, no investigation of further complaints)

Case 2: Patient presents to ED with stroke-like symptoms; stroke protocol started; computed tomography (CT) appeared normal; ED physician makes diagnosis of conversion reaction and gives psychiatric referral; symptoms improved, then worsened next day, and she presented to same ED; subtle findings and positive Babinski reflex; diagnosed with conversion disorder again and referred to psychiatric institute; ED physician noted patient “medically cleared and otherwise stable,” but requested electroencephalography (EEG) and neurology consult (cancelled by staff psychiatrist); no further tests ordered; repeated falls, urinary incontinence, and confusion during 3 wk as psychiatric inpatient; discharged to outpatient mental health facility despite poor ambulation; 18 days later, patient had severe disabling stroke; neurologist diagnosed stroke secondary to thrombotic thrombocytopenic purpura (TTP; cause of psychiatric symptoms) Analysis: psych-out error—all problems attributed to psychiatric diagnosis (patient had no previous psychiatric problems); term “medical clearance”—misleading and medicolegally dangerous; implies no organic basis for patient’s condition; better to describe patient as stabilized; caveat— physician should never rely on another physician to do his or her work; ED physician should have obtained neurologic consult himself; error to think problem neurologic, yet admit patient to psychiatric facility; other errors—diagnosis momentum; premature diagnostic closure (conversion disorder diagnosis of exclusion); once patient in psychiatric care, one-half of major medical diagnoses missed, so ED physician must rule out medical causes for delirium or confusion; errors of staff psychiatrist—vertical line thinking (concentrated on conversion disorder despite patient’s ataxia and urinary incontinence); overconfidence (canceled neurologic consult and EEG); diagnostic anchoring; premature closure

Case 3: Patient (39-yr-old woman) has history of 9 ED visits for complaints of chest pain during 6 mo following motor vehicle accident (MVA); no steps taken to diagnose chest pain; patient repeatedly told pain result of MVA trauma; patient had family history of risk factors (not obtained) and was smoker; patient had fatal cardiac arrest; $2 million awarded Analysis of case 3: fundamental attribution error—patient labeled “frequent flyer”; problem attributed to disposition of patient rather than to underlying medical condition; malingering, secondary gain, possible drug-seeking behavior, all attributed to patient over series of visits negative countertransferance—ED physician develops dislike of patient because of repeated visits diagnostic anchoring—also fostered by repeat visits; posterior probability error—seventh, eighth, and ninth physicians to see patient continue diagnosis of chest wall pain from MVA other errors—diagnostic momentum; premature diagnostic closure possible solutions—ECG at triage; risk factor analysis; observation unit; low threshold for stress testing in patients complaining of chest pain