Purpose: With the growing importance of professionalism in medical education, it is imperative to develop professionalism assessments that demonstrate robust validity evidence. The Professionalism Mini-Evaluation Exercise (P-MEX) is an assessment that has demonstrated validity evidence in the authentic clinical setting. Identifying the factorial structure of professionalism assessments determines professionalism constructs that can be used to provide diagnostic and actionable feedback. This study examines validity evidence for the P-MEX, a focused and standardized assessment of professionalism, in a simulated patient setting.

Method: The P-MEX was administered to 275 pediatric residency applicants as part of a 3-station standardized patient encounter, pooling data over an 8-year period (2012 to 2019 residency admission years). Reliability and construct validity for the P-MEX were evaluated using Cronbach's alpha, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA).

Results: Cronbach's alpha for the P-MEX was 0.91. The EFA yielded 4 factors: doctor-patient relationship skills, interprofessional skills, professional demeanor, and reflective skills. The CFA demonstrated good model fit with a root-mean-square error of approximation of .058 and a comparative fit index of .92, confirming the reproducibility of the 4-factor structure of professionalism.

Conclusions: The P-MEX demonstrates construct validity as an assessment of professionalism, with 4 underlying subdomains in doctor-patient relationship skills, interprofessional skills, professional demeanor, and reflective skills. These results yield new confidence in providing diagnostic and actionable subscores within the P-MEX assessment. Educators may wish to integrate the P-MEX assessment into their professionalism curricula.