American College of Surgeons Objective Assessment of Skills in Surgery (ACS OASIS): A Formative Assessment of Junior...

The objective assessment of technical skills of junior residents is essential in implementing competency-based training and providing specific feedback regarding areas for improvement. An innovative assessment that can be easily implemented by training programs nationwide has been developed by expert surgeon educators under the aegis of the American College of Surgeons (ACS) Division of Education. This assessment, ACS Objective Assessment of Skills in Surgery (ACS OASIS) uses eight stations to address technical skills important for junior residents within the domains of laparoscopic appendectomy, excision of lipoma, central line placement, laparoscopic cholecystectomy, trocar placement, exploratory laparotomy, repair of enterotomy, and tube thoracostomy. The purpose of this study was to implement ACS OASIS at a number of sites to study its psychometric rigor.

The ACS OASIS was pre-piloted at two programs to establish feasibility and to gather information regarding implementation. Each skills station was 12 minutes long, and the faculty completed a checklist with 5 to 15 items, and a global assessment scale. The study was then repeated at three pilot sites and included 29 junior residents who were assessed by a total of 44 faculty. Psychometric data for the stations and checklists were collected and analyzed.

The pre-pilot sites were Geisinger and University of Tennessee Knoxville.Data were gathered from pilot sites that included Wellspan Health, Duke University, and University of California Los Angeles.

The mean checklist score for all learners was 76% (IQR of 66%-85%). The average global rating was 3.36 on a 5-point scale with a standard deviation of 0.56. The overall cut score derived using the borderline group method was at 68% with 34% of performances requiring remediation. Using this criterion, the average number of stations that were completed by each learner without need for remediation was five.The station discrimination index ranged from 0.27 to 0.65 (all above the threshold of 0.25), demonstrating solid psychometric characteristics at the station level. The internal-consistency reliability was 0.76 with SEM of 5.8%. The inter-rater reliability (intraclass correlation) was high at 0.73 with general agreement of 79% between the two raters. The station discrimination was at 0.45 (range of 0.27 to 0.65) indicating a high level of differentiation between high and low performers. Using the generalizability theory, the G-coefficient reliability was at 0.72 with the reliability projection flattening after 8 stations. Overall, 75% to 82% the faculty and learners rated ACS OASIS as realistic and beneficial.

ACS OASIS is a psychometrically sound technical skills assessment tool that can provide useful information for feedback to junior residents and support efforts to remediate gaps in performance.