Influence of experience with a set of simulated patients on diagnosis of simulated patients not previously diagnosed

Background and Purpose. Diagnoses, to be useful, should be accurate. The purpose of this study using fictitious patients and student judges was to test the theory that diagnostic errors would occur when students saw simulated patients who were similar to previously seen simulated patients. Subjects. Sixty physical therapist (PT) students and 60 nonphysical therapist (NPT) students were studied. Subjects were assigned randomly to one of three groups. Methods. Instructions to the three groups differed in terms of rules provided for diagnoses and instructions to remember the patients. Students first diagnosed the same eight fictitious patients five times. The students then diagnosed eight new patients with similar characteristics interspersed with the original eight patients. Half of the new patients had a diagnosis different from that of the most similar old patient. Results. Students who were given a rule for diagnosis made fewer errors than students who were not given a rule. Students in the PT group took longer but made fewer errors on the critical opposite-diagnosis new cases than did students in the NPT group. Conclusion and Discussion. The results do not provide support for the theory that diagnostic errors would occur when students saw patients who were similar to previously seen patients. Students in the PT group appeared to emphasize accuracy at the expense of speed in making their diagnoses. Given the nature of the simulated patient information and the mode of presentation used in the experiment, however, the conclusion that therapists in actual practice do not make errors because of the similarity between new and previously seen patients is not yet warranted. [Norton BJ, Strube MJ. The influence of experience with a set of simulated patients on diagnosis of simulated patients not previously diagnosed.