Validity Evidence for the Medical Student Core Physical Examination

Background: The Core Physical Exam (CPE) has been proposed as a set of key physical exam (PE) items for teaching and assessing PE skills in medical students, and as the basis of a Core + Cluster curriculum. Beyond the initial development of the CPE and proposal of the CPE and the Core + Cluster curriculum, no additional validity evidence has been presented for use of the CPE to teach or assess PE skills of medical students. As a result, a modified version of the CPE was developed by faculty at the University of Colorado School of Medicine (UCSOM) and implemented in the school’s clinical skills course in the context of an evolving Core + Cluster curriculum. Methods Validity evidence for the 25-item University of Colorado School of Medicine (UCSOM) CPE was analyzed using longitudinal assessment data from 366 medical students (Classes of 2019 and 2020), obtained from September 2015 through December 2019. Using Messick's unified validity framework, validity evidence specific to content, response process, internal structure, relationship to other variables, and consequences was gathered. Results Content and response process validity evidence included expert content review and rater training. For internal structure, a generalizability study phi coefficient of 0.258 suggests low reliability for a single assessment due to variability in learner performance by occasion and CPE items. Correlations of performance on the UCSOM CPE with other PE assessments were low, ranging from .00-.34. Consequences were explored through determination of a pass-fail cut score. Following a modified Angoff process, clinical skills course directors selected a consensus pass-fail cut score of 80% as a defensible and practical threshold for entry into precepted clinical experiences. Conclusions Validity evidence supports the use of the UCSOM CPE as an instructional strategy for teaching PE skills and as a formative assessment of readiness for precepted clinical experiences. The low generalizability coefficient suggests that inferences about PE skills based on the UCSOM CPE alone should be made with caution, and that the UCSOM CPE in isolation should be used primarily as a formative assessment.