1. Errors in the diagnostic process Hierarchy of Qualities in Medicine Frequency of diagnostic Errors Judgment under Uncertainty: Heuristics and Biases The Voytovich Solution Click to View Presentation

2. Hierarchy of Qualties in Medicine From patient‘s point of view Diagnostic Quality Therapeutic Quality Patient Satisfaction

3. Hierarchy of Qualties in Medicine Medical point of view Diagnostic Quality Therapeutic Quality Patient Satisfaction

4. Hierarchy of Qualities in Medicine und cognitive Processes Diagnostic Quality Therapeutic Quality Patient Satisfaction Skills Rules Knowledge

5. Frequency of diagnostic Errors Follow-up Autopsy Study Medizinische Klinik USZ 1972-1982-1992-2002 Lancet 2000;355:2027-31 Random Selection of 100 patients in each year Autopsy Rate above 90% until 1992, in the year 2002 Reduction to 53%, complete Autopsy Classification of diagnostic Errors according to Goldman

6. Classification of diagnostic errors Goldman et al NEJM 1983:380: 1000-05 Major diagnostic Errors –Class I: Knowledge of correct Diagnosis would have led to Survival –Class II: Knowledge of correct Diagnosis would not have affected Survival (too ill, no Treatment available) Minor diagnostic Errors –Class III: Missed Diagnosis but not cause of Death –Class IV: Occult, clinically not diagnosable Entity of epidemiological Interest eg Gallstones

7. Major Diagnostic Errors 1972-2002

8. Minor Diagnostic Errors 1972-2002

9. Class I+II vs. Class III+IV

10. Correct Diagnosis 1972-2002

11. Autopsy Rate and class I Errors over time Kaveh G et al, JAMA 2003: 289:2849-56

12. Frequency of class I Errors Klasse IAutopsie- Fehlerrate Medizin+ IPS (USZ) 2002 2% 53% Med-IPS (Mayo-Clinic) 1998-20004% 33% Med-IPS (Paris) 1995-9810.2%53% Med-IPS (Leuven,Belgien) 199616% 93% 32 Spitäler in USA 198413% 30% Medizin (Boston, USA) 198412% 40% Arch Int Med 2004:164;389; Mayo Clin Proc 2000:75:562; Ann Thorac Surg 1997:64:380; JAMA1987:258:339; Mayo Clin Proc. 2003;78:947-50. NEJM 1988:318;1249

13. Autopsy: Gold Standard for clinical Diagnosis? Pelletier et al J Gen Intern Med 1989:4;300-03

14. Autopsy: Gold standard for clinical diagnosis? Pelletier et al J Gen Intern Med 1989:4;300-03

15. Representativness –Similarity with „typical“ examples stored in memory Availability –Recent expierence, painful memory Adjustment and Anchoring –Stick to early hypotheses despite new information Judgment under Uncertainty: Heuristics and Biases Tversky and Kahneman Science 1974:185:1124-31

17. Cognitive Mechanisms of diagnostic Errors according to A.E. Voytovich* Omission Premature Closure Inadequate Synthesis Wrong Formulations * J Med Educ 1985:60;302-07

18. Omission Most frequent Error Decreases with Experience  Consequences –Delayed or missed Diagnosis

19. Premature Closure Independent of Experience Correlates with Confidence (ie Overconfidence) in Relation to the actual Case Reflects estimated Frequency of the diagnosed Disease  Consequences –Delayed or missed Diagnosis –Unnecessary Therapies –False Sense of Confidence if Error is not detected

20. Inadequate Synthesis Correlates with Experience  Consequences –Unnecessary Investigations –Delayed Treatment

21. Cognitive Mechanisms of diagnostic Errors according to A.E. Voytovich* Omission Premature Closure Inadequate Synthesis Wrong Formulations * J Med Educ 1985:60;302-07

22. Lancet 2000:355;2027-31

23. Major Diagnostic Errors 1972-2002

24. Sensitivity and Specificity 1-Sensitivity: Rate of missed Diagnoses (false negative rate) 1-Specificity: Rate of wrong Diagnoses (false positive rate)

25. Cardiovascular Diseases Sensitivity and Specificity 69% 85% 82% 86% 97% SensitivitätSpezifität 50 60 70 80 90 100 1972 1982 1992 p = 0.061p = 0.034

26. Lancet 2000:355;2027-31

27. Infectious Diseases Sensitivity and Specificity 25% 100% 67% 100% 86% 99% SensitivitätSpezifität 0 20 40 60 80 100 1972 1982 1992 nsp = 0.036

28. Neoplastic Diseases Sensitivity and Specificity 89% 92% 88% 97% 96% SensitivitätSpezifität 70 75 80 85 90 95 100 1972 1982 1992 ns

29. Difficulties in learning from Experience Lack of Search for and use of disconforming Evidence Lack of outcome Information Use of unaided Memory for coding, storing and retrieving outcome Information

30. Summary and Proposal Major diagnostic Errors occur despite an ever increasing repertory of diagnostic Procedures 85% of serious diagnostic Errors can only be detected by Autopsy Analysis of error mechanism can be helpful in the Discussion and Prevention of diagnostic Errors Minimum Autopsy rate of 30% along with a yearly Report on diagnostic Errors should be mandatory for Accreditation of medical Clinics