title: Do physicians know when their diagnoses are correct? Implications for decision support and error reduction.
abstract: OBJECTIVE
  This study explores the alignment between physicians' confidence in their diagnoses and the "correctness" of these diagnoses, as a function of clinical experience, and whether subjects were prone to over-or underconfidence.
  
  
  METHODS
  Prospective, counterbalanced experimental design.
  
  
  METHODS
  Laboratory study conducted under controlled conditions at three academic medical centers.
  
  
  METHODS
  Seventy-two senior medical students, 72 senior medical residents, and 72 faculty internists.
  
  
  METHODS
  We created highly detailed, 2-to 4-page synopses of 36 diagnostically challenging medical cases, each with a definitive correct diagnosis. Subjects generated a differential diagnosis for each of 9 assigned cases, and indicated their level of confidence in each diagnosis.
  
  
  RESULTS
  A differential was considered "correct" if the clinically true diagnosis was listed in that subject's hypothesis list. To assess confidence, subjects rated the likelihood that they would, at the time they generated the differential, seek assistance in reaching a diagnosis. Subjects' confidence and correctness were "mildly" aligned (kappa=.314 for all subjects, .285 for faculty, .227 for residents, and .349 for students). Residents were overconfident in 41% of cases where their confidence and correctness were not aligned, whereas faculty were overconfident in 36% of such cases and students in 25%.
  
  
  CONCLUSIONS
  Even experienced clinicians may be unaware of the correctness of their diagnoses at the time they make them. Medical decision support systems, and other interventions designed to reduce medical errors, cannot rely exclusively on clinicians' perceptions of their needs for such support.
authors.affiliation: Center for Biomedical Informatics, University of Pittsburgh, Pittsburgh, PA 15213, USA. cpf@cbmi.pitt.edu
authors.forename: Charles P
authors.initials: CP
authors.lastname: Friedman
authors.forename: Guido G
authors.initials: GG
authors.lastname: Gatti
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Franz
authors.forename: Gwendolyn C
authors.initials: GC
authors.lastname: Murphy
authors.forename: Fredric M
authors.initials: FM
authors.lastname: Wolf
authors.forename: Paul S
authors.initials: PS
authors.lastname: Heckerling
authors.forename: Paul L
authors.initials: PL
authors.lastname: Fine
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Miller
authors.forename: Arthur S
authors.initials: AS
authors.lastname: Elstein
mesh_terms: D002983:Clinical Competence; D020000:Decision Support Systems, Clinical; D003661:Decision Support Techniques; D006801:Humans; D007388:Internal Medicine / Q000592:standards*; D007396:Internship and Residency; D007600:Judgment; D016014:Linear Models; D019300:Medical Errors / Q000517:prevention & control; D011446:Prospective Studies; D013337:Students, Medical