"The results in this study provide strong evidence to support a significant association between placements, final-year marks and degree classifications among not only UK but also international students...
Unlike international students, UK students are consistently and significantly influenced by prior academic achievement..."
Caveat: This research refers to finance rather then STEM students.
The impact of placements on the academic performance of UK and international students in higher education. Studies in Higher Education, 31 Jul 2014. doi: 10.1080/03075079.2014.943658
Motivated by an increasing number of international students in UK higher education, this study investigates the effect of year-long placements on the academic performance of 268 accounting and finance students enrolled between 2006 and 2009. The results show differences between UK and international students although both statistically and significantly increase their final-year marks and their chance to obtain a good degree (first or 2.1) following placements. UK sandwich students outshine international sandwich students in the final year, while UK full-time students significantly underperform international full-time students in the first year only. The academic performance of UK students can be partly explained by prior academic achievement and gender but that of international students is not related to any of these individual factors. There is evidence of self-selection among UK sandwich students since they outperform UK full-time students at all levels, while no such a pattern is found among international students.