BACKGROUND: Preceptors must respond to trainees' medical errors, but little is known about what factors influence their responses.

METHOD: A total of 115 primary care preceptors from 16 medical schools responded to two medical error vignettes involving a trainee. Nine trainee-related factors were randomly varied. Preceptors indicated whether they would discuss what led to the error, provide reassurance, share responsibility, express disappointment, and adjust their written evaluation of the trainee.

RESULTS: Almost all preceptors would discuss what led to the error; relatively few would express disappointment. The trainee's prior history of errors, knowledge level relative to peers, receptivity to feedback, training level, emotional reaction, offering to apologize, and offering an excuse were predictive of preceptors' responses; gender and time-in-office were not.

CONCLUSION: This study identified seven trainee-related factors as predictive of preceptors' responses to medical errors. More research is needed to identify other influential factors, and to improve teaching from medical errors.