ClinicalReasoning2:Howdoctorsthink

DrNicolaCooperMBChBFAcadMEdFRCPEFRACPConsultantPhysician&HonoraryClinicalAssociateProfessor

Therearetwoclinicalreasoningworkshopsinthefirstyear.

Bytheendofthis sessionyoushould:

• Knowwhat‘reasoning’means

• Understandwhatismeantby‘rationality’inmedicine

• Beabletodescribedualprocesstheory

• Knowwhatcognitivebiasesareandtheirroleindiagnosis

Learningobjectives

‘Medicaleducationdoesagoodjobofimpartingthenecessaryknowledgetowould-bepractitionersbuthasbeenlesseffectiveataddressingthequestionofhowtheyshouldsubsequentlythinkabouttheknowledgetheyhavepainstakinglyacquired.’

Croskerry,P.Therationaldiagnostician.In:CroskerryP,CosbyK,GraberMLandSingh

Whatismeantby‘clinicalreasoning’?

‘Aclinician’sabilitytomakedecisions,oftenwithothers,basedontheavailableclinicalinformation,whichincludeshistory(sometimesfrommultiplesources),physicalexaminationfindingsandtestresults– againstabackdropofuncertainty.[It]alsoincludeschoosingappropriatetreatments(ornotreatmentatall)anddecision-makingwithpatientsand/ortheircarers.’

CooperN&FrainJ[Eds].ABCofClinicalReasoning.Wiley,2016.

Whatisclinicalreasoning?

Inalldefinitionsintheliterature,several‘components’(i.e.elementsofalargerwhole)oftheclinicalreasoningprocessaredescribed:

• History• Physicalexamination• Useandinterpretationofdiagnostictests• Reasoning/rationality• Shareddecisionmaking(withpatients,carers,teams,guidelinesetc.)

• Formalandexperientialknowledgeofmedicine

Whatisclinicalreasoning?

Whydoesclinicalreasoningmatter?

Thescaleofdiagnosticerror

• 1in10diagnosesareincorrect

• Diagnosticerrorcausessignificantharm

• Diagnosticerroraccountsfor40,000– 80,000deathsannuallyintheUS,somewherebetweenbreastcanceranddiabetes

• Chancesare,wewillallexperienceadiagnosticerrorinourlifetime

USInstituteofMedicine.(2013).25-yearsummaryofUSmalpracticeclaimsfordiagnosticerrors1986-2010:ananalysisfromtheNationalPractitionerDataBank.BMJQual Saf;22(8):672-680

Results-‘System-relatedfactorscontributedtodiagnosticerrorin65%ofthecasesandcognitivefactorsin74%… themostcommoncognitivefactorsinvolvedfaultysynthesis.’

SherbinoJ&NormanGR.(2014).AcademicEmergencyMedicine;21(8):931-933.

‘Theprevailingopinionthatdiagnosticerrorisacognitiveprocessingerror… isincorrect.Thisperspectivepresupposesthatalloftheavailableknowledgeispresent… Incontrast,adiagnosticerrormayreflectnotaprocessingerror,butanincompleteknowledgebaseorinadequateexperience.’

Thecomponentsofclinicalreasoning

Basic science

& clinical medicine

Shared decision-making*

Evidence-based physical

examination

Evidence-basedhistory

Reasoning/rationality

Use and interpretation of diagnostic

tests

Clinical Reasoning

Whydoes‘reasoning’mean?

Reasoningisaphilosophicalterm

‘Touseone'smindtoformopinionsandjudgements,reachlogicalconclusions,deduce,etc.’

Itincludesformallogicalreasoning(e.g.deduction,induction,abduction)andinformalintuitivereasoning.

TheChambersDictionary13th Ed.Chambers,2014.

Whatismeantby‘rationality’inmedicine?

CroskerryP.Therationaldiagnostician.In:CroskerryP,CosbyK,GraberM&SinghH.[Eds].Diagnosis:interpretingtheshadows.CRCPress,2017.

Themajorcomponentsofrationalityinmedicine

Individualcharacteristics

Peoplehavedifferentthinkingdispositions:

• Tendencytoseekinformation• Tendencytolookforevidence• Tendencytoanalyse,weighthingsup,beforedeciding• Healthyskepticism• Awarenessofcontext• Tendencytoreflect/thinkabouttheirownthinking

Experienceandthecognitivemiserfunction

Source:NationalGeographicChannel.

Dualprocesstheory

Clinicalreasoningandmemory

EvaKetal.(2002).Expert/novicedifferencesinmemory:areformulation.Teachingandlearninginmedicine;14:257-263SchmidtHG&Boshuizen HPA.(1993).Ontheoriginofintermediateeffectsinclinicalcaserecall.Memoryandcognition;21:338-351

Abatandaballcost£1.10intotal.Thebatcosts£1morethantheball.Howmuchdoestheballcost?

KahnemanD.Thinking,fastandslow.AllenLane,2011.

Dualprocesstheory

System1• Intuitive,heuristic(patterns)• Automatic,subconscious• Fast,effortless• Low/variablereliability• Vulnerabletoerror• Highlyaffectedbycontext• Highemotionalinvolvement

System2• Analytical,systematic• Deliberate,conscious• Slow,effortful• High/consistentreliability• Lesspronetoerror• Lessaffectedbycontext• Lowemotionalinvolvement• Requiresaccesstoworkingmemory

Dualprocesstheory

Adapted from Croskerry P. A universal model of diagnostic reasoning. Academic Medicine 2009; 84(8): 1022-1028.

Cognitivebiasesaresubconsciouserrorsinperception,judgementandinterpretationofinformation,andtheyareprevalentineverydaylife:'Toerrishuman'.

Cognitive biases

Socialbiases

Memorybiases

Decisionmakingbiases

Probability/beliefbiases

Casehistory(seeworksheet)

Spotthecognitivebiasesatplay

Subconsciouserrors

AnchoringWhenwefixonaparticularbitofinformation,leadingustothinkinaconstrainedway

ConfirmationbiasTendencytolookforconfirmingevidencetosupportourinitialhypothesisratherthanlookingfordisconfirmingevidencetorefuteit

DiagnosticmomentumTendencyforaparticulardiagnosistostickdespitelackofsupportingevidence

SearchsatisficingFromthewords‘satisfy’ and‘sufficient’ - whenwestopsearchingbecausewehavefoundsomethingthatfitsorisconvenient,insteadofsystematicallylookingforthebestalternative

Diagnosticmomentum

• Tendencyforaparticulardiagnosistostickdespitelackofsupportingevidence

• ‘Likeaboulderrollingdownamountain,thediagnosisgathersmomentum,crushingallelseinitspath’

• Usuallyinvolvesseveralintermediaries,includingthepatient

•Oftenstartsasanopinion,notnecessarilymedical,andpassedwithincreasingcertaintyfromonepersontothenext

•Diagnosticlabelsbecomeparticularly‘sticky’ onceapatienthasbeenseenbyaconsultant

Wife:‘I’mworried

you’rehavinga

heartattack’

Patient:‘ItfeelslikeI’mhavinga

heartattack…’

Paramedic:‘52-year-oldmalewithpossibleACS.’

Nurse:‘Youknowthatman

with?ACSincubicle12?’

Doctor:Documents‘possibleACS’innotes…

‘Biasshouldbeconsideredanormaloperatingcharacteristicofthehumanbrain– biasesareeverywhereandhavethepotentialtoinfluencealmosteverydecisionwemake.’

CroskerryP.Bias:anormaloperatingcharacteristicofthediagnosingbrain.Diagnosis2014;1:23-7

DIAGNOSTICERROR

EXTERNALFACTORSDistractionsCognitiveloadDecisiondensityTimepressures

AmbientconditionsInsufficientdataTeamfactorsPatientfactorsPoorfeedback

INTERNALFACTORSKnowledgeTraining

Beliefs/valuesEmotions

Sleep/fatigueStress

Affective/physicalillness

OverconfidenceRisk-takingbehaviour

COGNITIVEBIASES/ERRORSUseofintuitive

(System1)decision-makingprocesses

Factorsincreasingthelikelihoodofdiagnosticerror

Cognitivebiasesanderrors:whatcanwedoaboutit?

Results-‘System-relatedfactorscontributedtodiagnosticerrorin65%ofthecasesandcognitivefactorsin74%… themostcommoncognitivefactorsinvolvedfaultysynthesis.’

SherbinoJ&NormanGR.(2014).AcademicEmergencyMedicine;21(8):931-933.

‘Theprevailingopinionthatdiagnosticerrorisacognitiveprocessingerror… isincorrect.Thisperspectivepresupposesthatalloftheavailableknowledgeispresent… Incontrast,adiagnosticerrormayreflectnotaprocessingerror,butanincompleteknowledgebaseorinadequateexperience.’

Reflection is consistently beneficial

230 Evans, Stanovich

dual-process views, Newstead (2000) argued that “Epstein, Pacini, Denes-Raj, and Heier (1996) found that supersti-tious and categorical thinking, which might be supposed to be part of System 1, produced no significant correla-tions, either positive or negative, with Faith in Intuition (System 1)” (p. 690). But superstitious thinking signals a mode of thought, not a type—and this disposition is not at all an indicator of the functioning of Type 1 pro-cessing. It is a thinking disposition involving epistemic regulation—a Type 2 function.

Modes of processing—more commonly termed think-ing dispositions—are well represented in Stanovich’s (2009a, 2009b, 2011) tripartite model of mind displayed in its simplest form in Figure 1. In the spirit of Dennett’s (1996) book Kinds of Minds, the set of autonomous sys-tems (the source of Type 1 processing) is labeled as the autonomous mind, the algorithmic level of Type 2 pro-cessing the algorithmic mind, and the reflective level of Type 2 processing the reflective mind. Dennett’s “kinds of minds” terminology refers to hierarchies of control rather than separate systems. Two levels of control are associated with Type 2 processing and one with Type 1 processing. The autonomous set of systems (TASS) will implement their short-leashed goals unless overridden by an inhibitory mechanism of the algorithmic mind. But override itself is initiated by higher level control. That is, the algorithmic level is subordinate to higher level goal states and epistemic thinking dispositions. These goal states and epistemic dispositions exist at what might be termed the reflective level of processing—a level

containing control states that regulate behavior at a high level of generality. Such high-level goal states are com-mon in the intelligent agents built by artificial intelligence researchers (A. Sloman & Chrisley, 2003).

The difference between the algorithmic mind and the reflective mind is captured in the well-established distinc-tion in the measurement of individual differences between cognitive ability and thinking dispositions (and repre-sented in Fig. 1). The former are measures of the ability of the algorithmic mind to sustain decoupled representa-tions (for purposes of inhibition or simulation, see Stanovich, 2011). In contrast, thinking dispositions are measures of the higher level regulatory states of the reflec-tive mind: the tendency to collect information before making up one’s mind, the tendency to seek various points of view before coming to a conclusion, the disposi-tion to think extensively about a problem before respond-ing, the tendency to calibrate the degree of strength of one’s opinion to the degree of evidence available, the tendency to think about future consequences before tak-ing action, and the tendency to explicitly weigh pluses and minuses of situations before making a decision.

Thus, thinking disposition measures are telling us about the individual’s goals and epistemic values—and they are indexing broad tendencies of pragmatic and epistemic self-regulation at a high level of cognitive con-trol. Continuous variation in both cognitive ability and thinking dispositions can determine the probability that a response primed by Type 1 processing will be expressed—but the continuous variation in this probability in no way

ReflectiveMind

(individual differences in rational thinkingdispositions)

AlgorithmicMind

(individual differencesin fluid intelligence)

AutonomousMind

(few continuous individual differences)

Type 2Processing

Type 1Processing

Fig. 1. The locus of continuous individual differences in Stanovich’s tripartite model of the mind.

by Richard West on May 9, 2013pps.sagepub.comDownloaded from Stanovich KE. (2011). Rationality and the reflective mind. Oxford University Press.

Reflection during case-based learning

Forexample–

• Listthefindingsthatsupportthediagnosis• Listthefindingsthatgoagainstthediagnosis• Listthemissingfindingsyouwouldexpecttobepresentifthis

isthediagnosis• Listalternativediagnoses…

“What’stheevidenceforthisdiagnosis?Whatelsecouldthisbe?”(Engagingthereflectivemind).

Schmidt HG & Mamede S. (2015). How to improve the teaching of clinical reasoning: a narrative review and a proposal. Medical Education; 49: 961-973.

LearningstrategiesthatfacilitateCRdevelopment

BrownPC,Roediger HL,McDanielMA.(2014).Makeitstick:thescienceofsuccessfullearning.HarvardUniveristy Press.

Practiceiscriticalforlearning,withcorrectivefeedbackasnecessary.

Strategiesthatbuildunderstandingaremoresuccessful.

‘Desirabledifficulties’thatelicitmoreerrorsareoftenbeneficial:o Distributed(spaced)practice>massedpracticeo Mixedpractice>massedpracticeo Retrievalpractice(lowstakesquizzing)>repeatedstudy

There are learning strategies, not learning styles

Therearetwoclinicalreasoningworkshopsinthefirstyear.

Bytheendofthis sessionyoushould:

• Knowwhat‘reasoning’means

• Understandwhatismeantby‘rationality’inmedicine

• Beabletodescribedualprocesstheory

• Knowwhatcognitivebiasesareandtheirroleindiagnosis

Learningobjectives

Further resources