EFFECTIVE DECISION MAKING

Tom

ERRORS ARE DUE TO FLAWS IN

THINKING, NOT TECHNICAL MISTAKES

“Always look both ways when you go through a green light”

Case 1

60 year old man transferred from Albany hospital BG: RA on MTX, obese, ex-smoker

Presented to Albany 5/7 prior

SOB / cough / fevers – treated for CAP

Associated CP Troponin +

Dual antiplatelets commenced

Day 4

Day4: Episode of sig. hypotension and “coffee ground” vomit

Hb 120 70

Stabalized post-fluid and blood resuscitation

Transferred to SCGH for gastroscopy

PPI infusion

Day 5

S/by Gastroenterology & Cardiology

PR –ve, not for scope

Continue dual antiplatelets

Admitted under MAU

Patient feels well

Hb 75 despite 2 x PRBC

No further malena / haematemesis

Day 6: Doctor, I’ve got this bruise on my back

#1 Using shortcuts / pattern recognitionAlso known as “representativeness bias”

Fitting presentation to known “illness script” Develop hypotheses with incomplete information Often used when working / acting quickly

#2 Confirmation bias#3 Anchoring bias

Attention to data that supports presumed dx Minimise data that contradicts dx

#4 Framing effect#5 Diagnostic momentum

“Transferring patient with pneumonia, ACS and hypotension secondary to GI bleed in context of dual antiplatelets”

Case 2: CT chest request

60 year old man, 80 pack year smoking hx CT chest for F/U lung nodules

83% radiologists missed the gorilla

#6 Search satisfaction

Tendency to stop searching for a diagnosis once you’ve found something

What else could this be?

Slow down and think again

Case 3

18 year old lady admitted at private hospital psychiatry unit for anorexia nervosa

BMI 14 Week 2:

Flu-like symptoms, dry cough, night sweats, fevers

Septic screen

Commenced IV Abx: Amoxycillin / Azithromycin

Systems enquiry: otherwise unremarkable

Day 5-7: Not improving

IV Abx broadened

Meropenem / Lincomycin

Multiple microbiological investigations –ve

Required long course IV Abx on d/c with HITH

3 months later

Sputum MCSAcid-fast bacilli

Direct molecular PCR test: Positive for M. tuberculosis complex

#7: “Common things are common”

When you hear hoof beats, first think horses but consider zebras too.

The next patient

50 year old man, day 5 admission with pneumonia and ongoing fevers despite IV antibiotics…

You ask the physiotherapist to do induced sputums ? AFB

… Your consultant suggests a repeat CXR

Evolving effusion and possible empyema

The next patient

#7 Availability bias

#7 Availability bias

Diagnosis based on what is most available, rather than what is most probable

Stop!

Case 4

56 year old man BIBA with angioedema and ? self-terminating seizure

PMHx: ETOH +++, BPAD, Head injury, no fixed address

Intubated on arrival, ICU o/n Extubated on day 2 Immunology r/v: angioedema likely 2’ry NSAID Discharged to medical ward

“I deserve to be okay”

Day 4: Eating breakfast Perseverant speech Examination otherwise NAD

Reviewed by consultant / team

Delirium: ETOH withdrawal / post-ICU

Benzodiazepines prescribed

“I deserve to be okay”

Later

EEG ordered: focal status epilepticus

MRI: epileptogenic lesion presumed secondary to previous head injury

#8 Attribution errors

Patients fitting a negative stereotype Diagnosis presumed to align with stereotype He deserved to be okay!

Case 5

85 year old Italian lady admitted with nausea, malaise and leg weakness.

+++ Family present at all times

Cont…

Thorough neurological examination Watched by 5 family members, interrupting

constantly, hysterical Pt’s weakness interpreted as give-way

Diagnosis: likely functional

Day 3

Neurology consult

Diagnosis: Gullain Barre syndrome

#9 Negative counter-transference

• Doctors who feel dislike toward patients / family are more likely to:

• Interrupt during recitation of sx

• Lose patience required to consider alternatives

• Fix on a convenient dx

Case 6

Group of 3 ED registrars on a ski trip 28 year old female sustains high velocity fall

with hyperflexion Injury Severe lower cervical neck pain No “neurology” Ongoing significant pain for weeks Continues to ski, surf, work

3 weeks later

X-rays / CT:# C7 (lamina) and T1

spinous processes

#10 Positive countertransference

Positive emotions for the patient can also lead to errors

We focus on the information that aligns with the outcome we want for the patient

Apparent wellness can lead to“dysrationalia override”

Burn out

Exhaustion Impaired thinking Deflection Goal is to “clear the decks” Stop caring for patients

Temptation to work faster, use less effort (system 1)

Navigating safely

What can we do?

Metacognition: stepping back to reflect on the thinking process

The ability to realize which mode (system 1 or 2) you are in and move from one to the other

What doesn’t fit? Could there be something else?What diagnostic labels have been handed over?

Have I have missed another horse or a zebra?

Am I just seeing an “available” diagnosis?

Take extra care when you feel negative (or positive) emotions towards a patient

Are you paying attention?

Experts are able to recognize when patternsdo not fit their previous experience

And shift gears to use system 2 (slow down)

Cognitive check-points / diagnostic time-out

Phone a friend

Consider worst case scenario

Optimise work conditions

Supervision / team work

Clinical environment

Strategies

“If you listen to the patient, he is telling you the diagnosis”

– William Osler

Strategies

Learn from our mistakesAnalyse our own mistakes

Keep a mental (or written) log of mistakes

Build a supportive workplace where we can:Provide feedback

M&M: Analyse cognitive errors (and system errors)

Look after ourselves

Strategies

If I can’t talk about my mistakes:

How can I share with my colleagues?

How can I teach others not to

make the same mistakes?

Can I point out potential errors to my colleagues?

Build a supportive culture

Teaching juniors to drive

Conclusions

1. Misdiagnoses are commonly due to cognitive errors

2. Cognitive errors are commonly due to reliance on “system 1”

3. There are many strategies to avoid diagnostic error (metacognition)

Audience thoughts?