title: Predicting endoscopic diagnosis in the dyspeptic patient: the value of clinical judgement.
abstract: OBJECTIVE
  To compare the quality of chance-corrected clinical diagnosis in two groups of dyspeptic patients, using endoscopy as the diagnostic standard.
  
  
  METHODS
  Structured interview before endoscopy and clinical predictions of endoscopic diagnosis as either malignancy, peptic ulcer, oesophagitis or non-ulcer dyspepsia. The quality of the predictions was corrected for chance using iota-correction. Patients gave a provisional prediction of their own endoscopic diagnosis.
  
  
  METHODS
  Two endoscopy units in Odense and Svendborg, Denmark.
  
  
  METHODS
  Two groups of dyspeptic outpatients: (1) 1026 patients referred for open-access endoscopy and (2) 207 empirically managed patients randomly assigned to prompt endoscopy as part of a clinical trial.
  
  
  RESULTS
  The overall diagnostic validity for all diagnoses was equal in the two groups of patients (57 and 59%) and was mainly accounted for by positive predictive values for non-ulcer dyspepsia of 75%. Elimination of random accuracy for non-ulcer dyspepsia showed a validity of only 23 and 21%. Patients with a major pathologic lesion (cancer, ulcer, complicated oesophagitis) were misclassified clinically as non-ulcer dyspepsia in 36 and 38% of cases. The sensitivity of a clinical prediction of ulcer was only 52 and 36%, despite positive predictive values of 34%, and most valid when corrected for chance in the group of patients referred for open-access endoscopy. The patients' provisional diagnoses had no predictive value.
  
  
  CONCLUSIONS
  Clinical diagnosis in dyspepsia was unreliable as it misclassified one-third of patients with a major pathological lesion. Fifty percent of patients with ulcer were misclassified and that clinical diagnosis could only be confirmed in one-third of the cases. The chance-corrected validity of non-ulcer dyspepsia was only slightly better than chance. There was no predictive value of the patients' predictions of their own diagnosis.
authors.affiliation: Department of Medical Gastroenterology S, Odense University Hospital, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Bytzer
authors.forename: J M
authors.initials: JM
authors.lastname: Hansen
authors.forename: T
authors.initials: T
authors.lastname: Havelund
authors.forename: A
authors.initials: A
authors.lastname: Malchow-Møller
authors.forename: O B
authors.initials: OB
authors.lastname: Schaffalitzky de Muckadell
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002983:Clinical Competence; D004415:Dyspepsia / Q000175:diagnosis* / Q000209:etiology; D016099:Endoscopy, Gastrointestinal; D005260:Female; D006801:Humans; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D010817:Physician-Patient Relations; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity