title: Design of a study on suboptimal cognitive acts in the diagnostic process, the effect on patient outcomes and the influence of workload, fatigue and experience of physician.
abstract: BACKGROUND
  Diagnostic error is an important error type since diagnostic adverse events are regularly judged as being preventable and the consequences are considered to be severe. Existing research often focuses on either diagnostic adverse events or on the errors in diagnostic reasoning. Whether and when an incorrect diagnostic process results in adverse outcomes has not been studied extensively. The present paper describes the design of a study that aims to study the relationship between a suboptimal diagnostic process and patient outcomes. In addition, the role of personal and circumstantial factors on the quality of the diagnostic process will be examined.
  
  
  METHODS
  The research questions were addressed using several data sources. First, the differential diagnosis was assessed concurrently to the diagnostic process. Second, the patient records of 248 patients suffering from shortness of breath were reviewed by expert internists in order to reveal suboptimal cognitive acts and (potential) consequences for the patient. The suboptimal cognitive acts were discussed with the treating physicians and classified with the taxonomy of unsafe acts. Third, workload, fatigue and work experience were measured during the physicians work. Workload and fatigue were measured during the physicians shift using the NASA tlx questionnaire on a handheld computer. Physicians participating in the study also answered questions about their work experience.
  
  
  CONCLUSIONS
  The design used in this study provides insight into the relationship between suboptimal cognitive acts in the diagnostic process and possible consequences for the patient. Suboptimal cognitive acts in the diagnostic process and its causes can be revealed. Additional measurements of workload, fatigue and experience allow examining the influence of these factors on the diagnostic process. In conclusion, the present design provides a method with which insights in weaknesses of the diagnostic process and the effect on patient outcomes can be studied and opportunities for improvement can be obtained.
authors.affiliation: EMGO Institute for Health and Care Research, Department of Public and Occupational Health, VU University Medical Center, Amsterdam, The Netherlands. laura.zwaan@vumc.nl
authors.forename: Laura
authors.initials: L
authors.lastname: Zwaan
authors.forename: Abel
authors.initials: A
authors.lastname: Thijs
authors.forename: Cordula
authors.initials: C
authors.lastname: Wagner
authors.forename: Gerrit
authors.initials: G
authors.lastname: van der Wal
authors.forename: Daniëlle R M
authors.initials: DR
authors.lastname: Timmermans
mesh_terms: D000328:Adult; D002983:Clinical Competence; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D004417:Dyspnea / Q000150:complications / Q000175:diagnosis*; D005221:Fatigue / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D009426:Netherlands; D012107:Research Design; D012189:Retrospective Studies; D012307:Risk Factors; D018401:Sample Size; D011795:Surveys and Questionnaires; D016526:Workload