title: Virtual patients for assessment of medical student ability to integrate clinical and laboratory data to develop differential diagnoses: comparison of results of exams with/without time constraints.
abstract: BACKGROUND
  We have evaluated medical student ability in a problem-based learning course using a virtual patient (VP)-based exam with variable parameters for assessment purposes.
  
  
  METHODS
  A class of 155 second year medical students was assessed using a VP exam with unlimited access during a 1-week period; 2 years later, the identical exam was administered to 175 students with a 3-h time limit.
  
  
  RESULTS
  Students taking the exam without time constraints utilized approximately twice as much time than students with the time limit. Without the pressure of a time-limit, students utilized half as many inquiries of the patient history, physical, and lab/imaging tests than were used by students having a time constraint, indicating that the time limited students used a "shotgun approach" to try to collect as many "required" inquiries as possible. Most students (91%) taking the untimed exam were able to correctly diagnose the exam case but only 31% of the time limited students correctly diagnosed the VP exam case, despite their higher number of inquiries.
  
  
  CONCLUSIONS
  Our results demonstrate that an identical VP exam, administered with variables to compare untimed versus time-limited conditions, resulted in an unraveling of student's ability to integrate the data discovered during the process of progressive disclosure.
authors.affiliation: University of Toledo, USA.
authors.forename: William T
authors.initials: WT
authors.lastname: Gunning
authors.forename: Uno G H
authors.initials: UG
authors.lastname: Fors
mesh_terms: D002983:Clinical Competence; D003198:Computer Simulation; D003657:Decision Making; D003937:Diagnosis, Differential; D004504:Education, Medical, Undergraduate / Q000379:methods*; D004521:Educational Measurement / Q000379:methods; D006801:Humans; D009820:Ohio; D018794:Problem-Based Learning / Q000379:methods*; D012189:Retrospective Studies; D013997:Time Factors