Editorial Comment on: Validation of a Novel Cost Effective Easy to Produce and Durable In Vitro Model for Kidney-Puncture and Percutaneous Nephrolitholapaxy-Simulation by Klein et al.

One of the most challenging minimally invasive urologic surgery procedures to teach trainees is the percutaneous access to the upper collecting system for performance of percutaneous nephrolithotomy (PNL). This is an interesting report of a new, and purportedly easy to produce, in vitro model of porcine kidney and ureter embedded in a ballistic gel for training percutaneous renal access technique. ¹ While we gain a good understanding of how to construct and utilize the model, as educators we are left with a great deal of uncertainty as to the role of this tool in teaching PNL.

Minimally invasive urologic surgery educators do not need studies of outdated types of validity testing for simulation models. Validity evidence should not be for the simulator itself, but rather should apply to the interpretation of the performance scores obtained from using a specific simulator to make a judgment of competence or skill. ²

The competency-based medical education model focuses on the acquisition, maintenance, and enhancement of skills at various stages of competency during a surgeon's career. The demonstration of robust validity evidence provides educators with the ability to accurately assess competence. Studies demonstrating translation of surgical skill performance to the operating room as a result of a specific training curriculum, or predictive validity, are exceptionally rare but what educators really need. So although these educational researchers have developed a potentially important training tool for PNL, they have fallen short through the lack of predictive validity evidence and delineation of the model within an effective PNL curriculum. Owing to the limited validity evidence of this model, and small study group size that really makes it a proof-of-concept report, it presently will have minimal impact on the existing educational literature.

What the minimally invasive urologic surgery training community needs is robust validity evidence to support the judgment of competency made using simulation-based assessment tools. Remember, we are not looking to validate the simulator itself, but rather looking for validity evidence to support the judgments we make using the scores that result from trainees performing on the simulator and the ultimate impact this will have on patient outcomes and safety as trainees implement their learned skills on urologic patients.