EFFECTS OF A DECISION-SUPPORT SYSTEM ON THE DIAGNOSTIC-ACCURACY OF USERS - A PRELIMINARY-REPORT

Objectives: To assess the effects of incomplete data upon the output o f a computerized diagnostic decision support system (DSS), to assess t he effects of using the system upon the diagnostic opinions of users, and to explore if these effects vary as a function of clinical experie nce. Design: Experimental pilot study. Four clusters of nine cases eac h were constructed and equated for case difficulty. Definitive finding s were omitted from the case abstracts. Subjects were randomly assigne d to one of four clusters and were trained on the DSS prior to use. Su bjects: The study involved 16 physicians at three levels of clinical e xperience (six general internists, four residents in internal medicine , and six fourth-year medical students), from three academic medical c enters. Procedure: Each subject worked up nine cases, first without an d then with ILIAD consultation. They were asked to offer up to six pot ential diagnoses and to list up to three steps that should be the next items in the diagnostic workup. Effects of DSS consultation were meas ured by changes in the position of the correct diagnosis in the lists of differential diagnoses, pre- and post-consultation. Results: The DS S lists of diagnostic possibilities contained the correct diagnosis in 38% of cases, about midway between the levels of accuracy of resident s and attending general internists. In over 70% of cases, the DSS outp ut had no effect on the position of the correct diagnosis in the subje cts' lists. The system's diagnostic accuracy was unaffected by the cli nical experience of the users.