Evaluating laparoscopic skills, setting the pass/fail score for the MISTELS system

Background: The McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS) was developed to assess laparoscopic skills and to score them objectively. This system has been described previously. The purpose of the current study was to determine a pass/fail threshold. Methods: In this study, 165 individuals were tested and grouped according to their clinical competency in laparoscopic surgery. The noncompetent group consisted of medical students and surgical residents in their first 2 years of training (n = 83). The competent group consisted of chief general surgical residents in their last year of training, laparoscopy fellows, and practicing laparoscopic surgeons (n = 82). The Mann-Whitney U test was used to evaluate differences in task performance between the two groups. Results: There was a significant difference in total scores and individual MISTELS task scores between the noncompetent and competent laparoscopic surgeons (189 vs 372.5; p < 0.0001). By setting specific pass/fail total score thresholds (cutoff scores), competent surgeons can be discriminated from noncompetent surgeons. Conclusion: An objective pass/fail evaluation can be given to individuals tested with the MISTELS system.