The study provides insight as to why supervisors fail to fail the poorly performing student and resident. It also offers suggestions of how to support supervisors, increasing the likelihood that they will provide a valid ITER when faced with an underachieving trainee.

This novel evaluation tool successfully discriminated between junior and senior residents and identified surgical competency across various PGY levels regardless of procedure type. Multiple sources of evidence support the O-SCORE as a valid tool for the assessment of trainee operative competency.

The inhibiting and enabling factors to failing an underperforming trainee were common across the professions included in this study, across the 10 years of data, and across the educational continuum. We suggest that these results can inform efforts aimed at addressing the failure to fail problem.