RESUMO
OBJECTIVE: Virtual reality (VR) simulation-based training effectively improves novices' mastoidectomy skills. Unfortunately, learning plateaus at an insufficient level and knowledge on optimizing mastoidectomy training to overcome this plateau is needed. In this study, we aim to investigate how training on anatomically different temporal bone cases affects learning, including the effect on retention and transfer of skills. STUDY DESIGN: Randomized controlled trial of an educational intervention. SETTING: The Simulation Center at Copenhagen Academy for Medical Education and Simulation. PARTICIPANTS: Twenty-four medical students from the University of Copenhagen. INTERVENTION: Participants were randomized to practice mastoidectomy on either 12 anatomically varying (intervention group) or 12 identical (control group) cases in a VR simulator. At the end of training and again ~ 3 weeks after training (retention), learners were tested on a new VR patient case and a three-dimensional printed model. MAIN OUTCOME MEASURE: Mastoidectomy performance evaluated by blinded expert raters using a 26-item modified Welling Scale. RESULTS: The intervention and control groups' performance results were comparable at the end of training. Likewise, retention and transfer performances were similar between groups. The overall mean score at the end of training corresponded to approximately 70% of the possible maximum score. CONCLUSIONS: Simulation-based training using anatomical variation was equivalent to training on a single case with respect to acquisition, retention, and transfer of mastoidectomy skills. This suggests that efforts to expose novices to variation during initial training are unnecessary as this variation has limited effect, and-conversely-that educators can expose novices to naturally different anatomical variations without worry of hindered learning.