Testing internal consistency and construct validity during evaluation of performance in a patient simulator
The primary goal of this study was to test the items in a rating system developed to evaluate anesthesiologists' performance in a simulated patient environment. A secondary goal was to determine whether the test scores could discriminate between resident and staff anesthesiologists. Two 5-item clinical scenarios included patient evaluation and induction and maintenance of anesthesia. Rating scales were no response to the problem (score = 0), compensating intervention (score = 1), and corrective treatment (score = 2). Internal consistency was estimated using Cronbach's coefficient α. Scores between groups were compared using the Cochran-Mantel-Haenszel test. Subjects consisted of 8 anesthesiology residents and 17 university clinical faculty. The Cronbach's coefficient a was 0.27 for Scenario A and 0.28 for Scenario B. Two items in each scenario markedly decreased internal consistency. When these four items were eliminated, Cronbach's coefficient α for the remaining six items was 0.66. Faculty anesthesiologists scored higher than residents on all six items (P < 0.001). A patient simulator-based evaluation process with acceptable reliability was developed. Implications: The reliability of anesthesia clinical performance in a patient simulation environment was assessed in this study. Of 10 items, 4 were poor in the evaluation process. When these items were removed, the reliability of the instrument improved to a level consistent with other studies. Because faculty scored higher than resident anesthesiologists, the instrument also showed discriminant validity.