Cognitive Heuristics

1. Cognitive Heuristics Vignesh Narayanan, M.D Denver Health Medical Center

2. “An expert is a person who has made all the mistakes that can be made in a very narrow field” - Neils Bohr I think, therefore I am - Descartes,1664 err

3. Heuristics- definition • ‘Heuriskein’ – ‘to find’ or ‘discover’ (Greek) • subconscious rules of thumb • shortcuts in diagnostic reasoning • ‘Eureka’ has the same origin

4. Case presentation • 63 y.o female, could speak only Spanish • CC: chest pain, progressive dyspnea • HPI: Chest pain X 2 wks • sub-sternal, recurrent, episodic • non-radiating, non-exertional • worsened by deep inspiration • Other complaints: • progressive dyspnea x 2 wks • non-productive cough, no orthopnea/PND • subjective fevers – 3 wks

5. Case: continued • Past medical history • diabetic, hypertensive • osteomyelitis of L- 5th toe, amputation 2 mos PTA • CHF: diastolic dysfunction, EF > 55% • CKD: baseline creatinine of 1.6 • Medications: • lasix 120 mg BID, stopped 2 wks PTA • metoprolol, amlodipine, hydralazine, rosuvastatin • glargine & lispro

6. Case: continued • Surgeries • amputation of L- 5th toe 2 mo PTA • Social history • life long non-smoker, no alcohol • Family history • mom with ‘heart problems’ NOS • ten children • No allergies

7. Case: continued • Examination • vitals: T:36, HR: 71, BP: 100/75, RR: 18 • normal JVP, normal cardiac exam • bilateral diffuse crackles • no edema of ext’s • left 5th toe amputation site- normal • Labs/data • Na: 126, BUN: 48, Creat: 1.9 • WBC: 11K, TnI: normal • CxR: consistent with pulmonary edema • EKG: NSR, no new changes

8. Case: initial A & P • Chest pain/cough • pleuritic in nature • c/w acute bronchitis- p.o azithromycin • SOB: Pulmonary edema unlikely given nl JVP • “dry” by labs- hyponatremia, BUN/creat ratio • ? ILD- check PFT’s, HRCT, pulmonology consult • Acute on chronic renal failure: Likely volume depletion • check UA, U.lytes, U.Osm • substantiated by hyponatremia – IVF 500 ml NS • Subjective fevers, mild leukocytosis: occult infection ? • recent osteomyelitis- amputation site- well healed • check UA, ESR, CRP

9. Case: hospital day # 1 • Improvement in symptoms • Complaint: pain over left temple & behind ear • Exam: • HR: 81, BP: 105/60, RR: 18, Sat: 92% 2L NC • B/L diffuse crackles • Labs: • Na 135, creat 1.8, WBC: 11K • CRP: 170, ESR: 110 • Assessment: • dyspnea, hypoxia, diffuse crackles- ? ILD • pain L temple, elevated ESR, CRP- ? Temporal arteritis/PMR • Plan: • HRCT, PFT’s, rheumatology consult, echo

10. Case: hospital day # 2 • More pain L temple/behind ear • More SOB than admit • Exam: • nl vitals, 93% 4L NC • b/l diffuse crackles • Other labs • UA: 21-50 WBC • PFT: • restrictive lung defect • HRCT: • no ILD • b/l pleural & moderate pericardial effusions • coronary LAD calcification • Assessment/plan: • pleuro-pericardial effusions, temple pain, high ESR, CRP • suspect CVD • echo for dyspnea

11. Case: hospital day # 2 • Rheumatology: • no evidence of CVD by history or exam • alternate etiology for high CRP/ESR- r/o infection • tap pleural effusion, check labs • Pulmonology: • HRCT, PFT abnormalities likely due to CHF/pulmonary edema • diuresce with IV lasix

12. Remaining hospitalization • Infection W.U • sinus CT: nl mastoid • foot X ray- no OM • Treated for UTI • Dyspnea, O2 sat • much better with lasix • Echo: • global hypokinesis • EF lower than 2 mos ago • Discharged on day 4 • Diastolic failure with pulmonary edema • UTI • Atypical chest pain • Acute on CKD

13. 2 days after discharge • Outside hospital • chest pain, dyspnea • Cardiac arrest in ED • Coronary angiogram • near total block of LAD • PCI • doing well

14. Summary elderly woman with Chest pain investigated for several diagnoses (ILD, CVD, Infection) discharged with alternate diagnosis (diastolic CHF) Missed diagnosis eventually diagnosed with different disease (critical CAD)

15. Diagnosis Reason Make Decisions Formulate Judgments Cognitive Psychology (of diagnosis ) Therapy

16. Why we take shortcuts ER doctor Tom Brady • Lack of time • Memory • rationality is bounded Lehrer. How We Decide. HMH Press; 2009 Simon HA. Annu Rev. Psychology 1990; 41:1-19

17. Heuristics: ‘Shortcuts’ in diagnostic reasoning Pitfalls are repetitive & impalpable Reduce time, deliberation Wrong conclusions Shortcuts in reasoning Fever, cough, chest pain = Pneumonia Fever, cough, chest pain = Acute PE

18. ‘Availability’ heuristic • Does the English language have more words that start with the letter ‘r’ (or) more words that have the letter ‘r’ in the third position? Tversky & Kahneman- Cognitive Psychology. 1973;5: 207-32

19. ‘Availability’ Heuristic • Ease of recalling past cases • likelihood judged by easily ‘available’ past eg’s • More convenient than collecting & memorizing probabilities Common diagnoses are common Un-common diagnoses not considered High CRP = infection, inflammation High CRP = predicts CAD risks

20. ‘Anchoring’ Heuristic First impression - Best impression? Easier than constantly re-integrating evidence Anchored on lab values (Hyponatremia, CRP) Lack of one finding (Elevated JVP) Failure to check for disconfirming evidence

21. ‘Framing’ Heuristic atypical CP, serositis + suspected ILD ,temple pain + elevated ESR, CRP DM, recent toe OM + bronchitis + mastoid pain: ? sinusitis + abnormal UA, high CRP atypical angina, CAD risks + new decrease in EF, pulm edema + calcified LAD, high CRP Collagen vascular Dz Infectious process Serious CAD

22. Other heuristics, biases • ‘Blind Obedience’: • Technology • PFT “restrictive lung disease” • Superior authority • rheumatology- “consider infection” • ‘Premature Closure’ • reluctance to pursue alternate diagnoses • using evidence that seems confirmatory • dismissing evidence that is contradictory

23. Avoiding heuristic biases Problems to acknowledge • Many clinicians are unaware of their error* • too distal in time or place • lack of effective feedback • Overconfidence** • declining autopsy rates (<10%) • Sense of pessimism in the literature • “cognitive errors are high hanging fruits” • “the search for zero error rates is doomed from the start” *Redelmeier- Ann Intern Med 2005;142:115-120 ** Berner & Graber- Am J Med 2008;121:S2-S23

24. Strategies to minimize heuristic bias Diagnostic error Cognitive psychology approach Normative approach • - pay more attention • - be thorough • practice more • don’t forget this next time • awareness about heuristic biases • adding safeguards against reflexive decision making

25. Strategies to minimize heuristic bias • 2 core strategies • Metacognition • Cognitive forcing Gordian Knot

26. Strategy 1: Meta-cognitive training • Meta-cognition: “thinking about thinking” • 2 processes occurring simultaneously • awareness of learning process to monitor progress • adaptive strategies based on progress • Requires the clinician to • stand apart from his/her own thinking & observe it • recognize opportunities for intervention “If at first the idea does not sound absurd, then there is no hope for it ” - Albert Einstein Croskerry- Ann Emerg Med. 2003; 41: 1

27. Metacognition Crystal ball experience This plan is proven faulty & does not work. Please devise an alternate plan • Promotes open minded thinking • Helps to ‘step back’ and rethink • Ensures multiple possibilities are considered Graber et al. Acad Med. 2002;77(10):981-92 Mitchell DJ- J Behav Decis Making. 1989;2:25-38

28. Strategy 2: Cognitive forcing “Deliberate, conscious selection of a particular strategy in a specific situation to optimize decision making and avoid error” Croskerry- Ann Emerg Med. 2003; 41: 1

29. Some ‘pills’ for our cognitive ‘ills’ Reidelmeier D. Ann Intern Med 2005; 142(2): 115-120 Croskerry P. Acad. Med 2003; 78: 775-780

30. Experts might feel like…

31. Summary • Cognitive short-cuts: • due to lack of time & bounded rationality • Double edged swords • Overcome by • metacognition & cognitive forcing

32. Thanks! “Too often the shortcut, the line of least resistance, is responsible for evanescent and unsatisfactory success” -Louis Binstock