title: Is bias in the eye of the beholder? A vignette study to assess recognition of cognitive biases in clinical case workups.
abstract: Many authors have implicated cognitive biases as a primary cause of diagnostic error. If this is so, then physicians already familiar with common cognitive biases should consistently identify biases present in a clinical workup. The aim of this paper is to determine whether physicians agree on the presence or absence of particular biases in a clinical case workup and how case outcome knowledge affects bias identification.
  
  
  
  We conducted a web survey of 37 physicians. Each participant read eight cases and listed which biases were present from a list provided. In half the cases the outcome implied a correct diagnosis; in the other half, it implied an incorrect diagnosis. We compared the number of biases identified when the outcome implied a correct or incorrect primary diagnosis. Additionally, the agreement among participants about presence or absence of specific biases was assessed.
  
  
  
  When the case outcome implied a correct diagnosis, an average of 1.75 cognitive biases were reported; when incorrect, 3.45 biases (F=71.3, p<0.00001). Individual biases were reported from 73% to 125% more often when an incorrect diagnosis was implied. There was no agreement on presence or absence of individual biases, with κ ranging from 0.000 to 0.044.
  
  
  
  Individual physicians are unable to agree on the presence or absence of individual cognitive biases. Their judgements are heavily influenced by hindsight bias; when the outcome implies a diagnostic error, twice as many biases are identified. The results present challenges for current error reduction strategies based on identification of cognitive biases.
authors.affiliation: Institute of Medical Education Research Rotterdam, Erasmus MC, Rotterdam, The Netherlands.|Department of Public and Occupational Health, VU University Medical Center/EMGO Institute, Amsterdam, The Netherlands.
authors.forename: Laura
authors.initials: L
authors.lastname: Zwaan
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Sandra
authors.initials: S
authors.lastname: Monteiro
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Sherbino
authors.affiliation: Department of Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ilgen
authors.affiliation: Program for Educational Research and Development, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Betty
authors.initials: B
authors.lastname: Howey
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Norman
mesh_terms: D006801:Humans; D010820:Physicians / Q000523:psychology*; D011287:Prejudice / Q000523:psychology*; D011320:Primary Health Care; D011795:Surveys and Questionnaires
keywords: Cognitive biases; Diagnostic errors; Patient safety