Importance: Previous studies have shown that medical student mistreatment and burnout are common. However, few longitudinal data exist to describe how mistreatment and other learning environment experiences are associated with subsequent burnout and other student characteristics.

Objective: To examine the association between mistreatment and perceptions of the learning environment with subsequent burnout, empathy, and career regret among US medical students.

Design, setting, and participants: This cohort study analyzed data from the 2014-2016 Association of American Medical Colleges (AAMC) Medical School Year 2 Questionnaire (Y2Q) and 2016-2018 AAMC Graduation Questionnaire (GQ). Medical students from 140 allopathic medical schools who responded to both AAMC surveys were included in the analysis. Data were analyzed from December 1, 2019, to January 11, 2021.

Exposures: Self-reported medical student mistreatment (eg, experiences of negative behaviors and discrimination related to sex, race/ethnicity, and sexual orientation) and perceptions of the learning environment (Medical School Learning Environment Survey subscales for faculty, emotional climate, and student-student interactions).

Main outcomes and measures: Burnout, empathy, and career regret as measured by Oldenburg Burnout Inventory data for burnout, Interpersonal Reactivity Index scores for empathy, and a single item assessing career regret.

Results: Data from 14 126 medical students were analyzed; 52.0% were women, and the mean (SD) age was 27.7 (2.9) years at graduation. Mistreatment was reported by 22.9% of respondents on the Y2Q. In multivariable analysis adjusted for Y2Q measures, mistreatment reported on the Y2Q was associated with a higher exhaustion score (1.81 [95% CI, 1.60-2.02]), a higher disengagement score (0.71 [95% CI, 0.58-0.84]), and higher likelihood of career regret on the GQ (186 of 989 [18.8%]; all P < .001). A more positive emotional climate reported on the Y2Q was associated with a lower exhaustion score (for each 1-point increase, -0.05 [95% CI, -0.08 to -0.02]; P = .001) and lower disengagement score (for each 1-point increase, -0.04 [95% CI, -0.06 to -0.02]; P < .001) on the GQ. More positive faculty interactions on the Y2Q were associated with higher empathy score on the GQ (for each 1-point increase, 0.02 [95% CI, 0.01-0.05]; P = .04). Better student-student interactions were associated with lower odds of career regret during year 4 of medical school (odds ratio for each 1-point increase, 0.97 [95% CI, 0.95-1.00]; P = .04).

Conclusions and relevance: The findings of this cohort study suggest that medical students who experienced mistreatment and perceived the learning environment less favorably were more likely to develop higher levels of exhaustion and disengagement, lower levels of empathy, and career regret compared with medical students with more positive experiences. Strategies to improve student well-being, empathy, and experience should include approaches to eliminate mistreatment and improve the learning environment.