Socioeconomic status and informal preference signaling among medical school applicants

Medical school applicants engage in informal preference signaling by submitting letters of intent (which include a commitment to accept an admission offer) and letters of interest (which include no such commitment). Commitments are unenforceable and are based on an honor system. Applicants submit letters to medical schools before receiving financial aid offers, potentially disadvantaging low socioeconomic status (SES) applicants. This study describes postinterview communication patterns and analyzes associations among applicant demographics, letter submission rates, and admissions outcomes. It tests the hypothesis that low SES is negatively associated with letter of intent submission.

The authors collected postinterview communications from all interviewees at the Mayo Clinic Alix School of Medicine during 3 admissions cycles (2021-2023). Authors developed and validated codebook definitions for the 2 letter types. SES was defined using the Association of American Medical Colleges education-occupation indicator. Letter submission rates were compared using mixed-effects logistic regression.

Of 1,313 applicants, 1,109 submitted 1 letter or more. The sample included 257 (19.6%) low-SES and 1,056 (80.4%) non-low-SES applicants. Coders showed excellent interrater reliability (Gwet AC1 range, 0.89-0.995). Low-SES applicants submitted letters of intent with similar frequency to higher-SES applicants (33.9% [87/257] vs 33.5% [354/1,056]; odds ratio, 1.02; 95% CI, 0.76-1.37; P = .88) and submitted letters of interest at similar frequency (55.6% [143/257] vs 59.5% [628/1,056]; odds ratio, 0.86; 95% CI, 0.65-1.13; P = .27). Among 116 applicants who wrote letters of intent and were offered admission, 20 (17.2%) declined the admission offer.

There was no difference in letter of intent submission based on SES, and letter of intent submission was positively associated with matriculation. Among letter of intent writers who were offered admission, 1 in 6 declined. Undergraduate medical education may wish to consider a formalized preference signaling system to promote an honest and transparent application process.