title: Diagnostic reasoning and underlying knowledge of students with preclinical patient contacts in PBL.
abstract: BACKGROUND
  Medical experts have access to elaborate and integrated knowledge networks consisting of biomedical and clinical knowledge. These coherent knowledge networks enable them to generate more accurate diagnoses in a shorter time. However, students' knowledge networks are less organised and students have difficulties linking theory and practice and transferring acquired knowledge. Therefore we wanted to explore the development and transfer of knowledge of third-year preclinical students on a problem-based learning (PBL) course with real patient contacts.
  
  
  METHODS
  Before and after a 10-week PBL course with real patients, third-year medical students were asked to think out loud while diagnosing four types of paper patient problems (two course cases and two transfer cases), and explain the underlying pathophysiological mechanisms of the patient features. Diagnostic accuracy and time needed to think through the cases were measured. The think-aloud protocols were transcribed verbatim and different types of knowledge were coded and quantitatively analysed. The written pathophysiological explanations were translated into networks of concepts. Both the concepts and the links between concepts in students' networks were compared to model networks.
  
  
  RESULTS
  Over the course diagnostic accuracy increased, case-processing time decreased, and students used less biomedical and clinical knowledge during diagnostic reasoning. The quality of the pathophysiological explanations increased: the students used more concepts, especially more model concepts, and they used fewer wrong concepts and links. The findings differed across course and transfer cases. The effects were generally less strong for transfer cases.
  
  
  CONCLUSIONS
  Students' improved diagnostic accuracy and the improved quality of their knowledge networks suggest that integration of biomedical and clinical knowledge took place during a 10-week course. The differences between course and transfer cases demonstrate that transfer is complex and time-consuming. We therefore suggest offering students many varied patient contacts with the same underlying pathophysiological mechanism and encouraging students to link biomedical and clinical knowledge.
authors.affiliation: Department of General Practice, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Agnes D
authors.initials: AD
authors.lastname: Diemers
authors.affiliation: Department of Work and Social Psychology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands.
authors.forename: Margje W J
authors.initials: MW
authors.lastname: van de Wiel
authors.affiliation: Institute for Education, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands.
authors.forename: Albert J J A
authors.initials: AJ
authors.lastname: Scherpbier
authors.affiliation: Department of General Practice, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Baarveld
authors.affiliation: Department of Educational Development and Research, School of Health Professions Education (SHE), Maastricht University, Maastricht, the Netherlands.
authors.forename: Diana H J M
authors.initials: DH
authors.lastname: Dolmans
mesh_terms: D002983:Clinical Competence; D003937:Diagnosis, Differential; D004504:Education, Medical, Undergraduate / Q000379:methods*; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D009426:Netherlands; D018794:Problem-Based Learning / Q000379:methods*; D013337:Students, Medical