The Impact of Using Mean Versus Mode When Assessing Resident Competency

ABSTRACT Background  The Accreditation Council for Graduate Medical Education Milestone Project was implemented in 2014 to standardize assessments and progression of residents. While it is recommended that milestones not be used as tools for direct assessments of resident competency, many programs have used or adapted milestone tools for this purpose. Objective  We sought to explore use of the most frequent milestone level at which a resident was evaluated (ie, the mode), and compared this to the standard practice of using the arithmetic mean for summarizing performance. Methods  We reviewed all Family Medicine Milestone evaluations from 1 program for the first 2 academic years of milestone implementation. Mean and mode scores were calculated across 24 unique residents, 841 evaluation forms, and 5897 measurements. The proportion of overestimation errors (where the mean is at least 0.5 larger than the mode) and underestimation errors (where the mean is at least 0.5 less than the mode) were then compared ac...