Background: Medical students' career intentions often change between matriculation and graduation, yet little is known about the precise timing and dynamics of individual students' career decisions. This study expands on previous research by exploring the stability of individual students' career intentions over four years and by analyzing associations between unstable career intentions and students' characteristics.

Methods: Medical students from two classes were recruited into a cohort during their first academic year and completed a yearly survey over a four-year period (end of pre-clinical curriculum to graduation). Measures included career intention (specialty and practice type), personality, coping strategies, empathy, and motives for becoming a physician. The authors developed a score ranging from 0 to 10 quantifying instability of career intentions (0 = stable; 10 = unstable). The distribution of the score was analyzed descriptively, and the association between the score and other variables was quantified using a stepwise beta regression model.

Results: The sample included 262 students (61% females). The mean score was 3.07 with a median of 3. 18% of students (N = 46) did not change their specialty intention over the four years, whereas 10% (N = 26) changed every year. No further subgroups were identified between these extremes. An intention to work in private practice in year 3 and the motive care for patients were significantly associated with more stable career intentions.

Conclusion: Most students are situated on a continuum between the two extremes of being firmly committed and undecided. Extrinsic factors may be more important drivers of these fluctuations than personal characteristics and should be explored in future research. This study's findings also provide avenues for supporting students in their career decision-making.