In-group bias in residency selection

More than half of all Canadian medical graduates match to residency programs within the same university as their medical school. Here we describe two studies designed to explore whether there is partiality for internal applicants in the resident selection process.

We first performed an observational study in which we compared the ratings of 14 'internal' and 89 'external' applicants to the University of Calgary Internal Medicine Training Program by resident and faculty raters. Following this we then asked residents to rate anonymous application packages in which we manipulated applicants' affiliation to our training program.

In our first study, we found that residents rated internal applicants significantly higher for both application packages (mean (SD)) rating for internal versus external applicants (4.86 (0.36) vs. 4.36 (0.57), d = 1.05, p = 0.002) and interviews (4.93 (0.27) vs. 4.36 (0.7), d = 1.07, p = 0.003). There was no difference in the faculty ratings of internal and external applicants. In our second study, we found that residents rated applicants with an affiliation to our program - either attending the local medical school or having completed an elective - higher than applicants with no affiliation to our program.

Our finding support in-group bias during resident selection, possibly due to the interdependent relationship between residents and students. Considering the career implications of residency matching, we feel that further studies are needed to identify and mitigate sources of bias in the residency application process.