Introduction Not all medical students who intercalate research degrees go on to completion. No study to date has investigated the specific reasons. Understanding this minority would fill an important research gap.

Methods A list was obtained of intercalating medical students who enrolled at our institution between 1995 and 2014. Students who withdrew from an intercalated research degree were then invited to complete an online survey via email.

Results Over the study period, 178 medical students commenced an intercalated honours or PhD degree with their medical degree, and 13 students withdrew from that program, giving an overall attrition rate of 7.3%. Students who withdrew from the intercalated degree were also more likely to withdraw from their medical degree (40%); this is compared with 3.6% of students who completed the intercalated degree, but eventually withdrew from their medical degree.

Discussion Demographics of this cohort were not dissimilar to those of completing students. Although withdrawing students had a higher exit rate from the medical degree, the rate of research involvement remained similar pre- and post-intercalation. The most commonly cited reasons for withdrawal were decreased satisfaction with research, and conflict with supervisors.