Introduction: Intercalated BScs (iBScs) are an optional part of undergraduate (UG) medicine courses in UK, Eire, Australia, New Zealand, the West Indies, Hong Kong, South Africa and Canada, consisting of advanced study into a particular field of medicine, often combined with research. They potentially improve students' skills and allow exploration of specific areas of interest. They are, however, expensive for institutions and students and delay workforce entry. There is conflicting evidence about their impact.
Methods: A mixed-method systematic review (meta-analysis and critical interpretive synthesis) of the biomedical and educational literature, focusing on the impact of iBScs on UG performance, skills, and career choice, and to explore students' and other stakeholders' opinions about iBScs.
Results: In the meta-analytic part of this review, we identified five studies which met our predetermined quality criteria. For UG performance, two studies using different methodologies report an improvement in UG performance; one study reported an Odds Ratio [OR] of 3.58 [95% CI 1.47-8.83] and the second reported a significant improvement in finals scores (1.27 points advantage 95% CI 0.52-2.02). One study reported a mixed result, while two studies showed no improvement. Regarding skills and attitudes, one paper suggested iBScs lead to the development of deeper learning styles. With regard to subsequent careers, two studies suggested that for those students undertaking an iBSc there is an increased chance following an academic career [ORs of 3.6 (2.3-5.8) to 5.94 (3.6-11.5)]. Seven of eight studies (with broader selection criteria) reported that iBSc students were less likely to pursue GP careers (ORs no effect to 0.17 [0.07-0.36]). Meta-analysis of the data was not possible. In the critical interpretative synthesis analysis, we identified 46 articles, from which three themes emerged; firstly, the decision to undertake an iBSc, with students receiving conflicting advice; secondly, the educational experience, with intellectual growth balanced against financial costs; finally, the ramifications of the iBSc, including some suggestion of improved employment prospects and the potential to nurture qualities that make "better" doctors.
Conclusion: Intercalated BScs may improve UG performance and increase the likelihood of pursuing academic careers, and are associated with a reduced likelihood of following a GP career. They help students to develop reflexivity and key skills, such as a better understanding of critical appraisal and research. The decision to undertake an iBSc is contentious; students feel ill-informed about the benefits. These findings could have implications for a variety of international enrichment programmes.