Evaluation of three sources of validity evidence for a laparoscopic duodenal atresia repair simulator

Laparoscopic duodenal atresia (DA) repair is a relatively uncommon pediatric operation requiring advanced minimally invasive skills. Currently, there are no commercial simulators available that address surgeons' needs for refining skills associated with this procedure. The purposes of this study were (1) to create an anatomically correct, size-relevant model and (2) to evaluate the content validity of the simulator.

Radiologic images were used to create an abdominal domain consistent with a full-term infant. Fetal bovine tissue was used to complete the simulator. Following Institutional Review Board exempt determination, 18 participants performed the simulated laparoscopic DA repair. Participants completed a self-report, six-domain, 24-item instrument consisting of 4-point rating scales (from 1=not realistic to 4=highly realistic). Validity evidence relevant to test content and response processes was evaluated using the many-facet Rasch model, and evidence of internal structure (inter-item consistency) was estimated using Cronbach's alpha.

The highest observed averages were for "Value as a training and testing tool" (both observed averages=3.9), whereas the lowest ratings were "Palpation of liver" (observed average=3.3) and "Realism of skin" (observed average=3.2). The Global opinion rating was 3.2, indicating the simulator can be considered for use as is, but could be improved slightly. Inter-item consistency was high (α=0.89).

We have successfully created a size-appropriate laparoscopic DA simulator. Participants agreed that the simulator was relevant and valuable as a learning/testing tool. Prior to implementing this simulator as a training tool, minor improvements should be made, with subsequent evaluation of additional validation evidence.