RESEARCH ARTICLE Basic life support is effect s S

Full list of author information is available at the end of the articleBackground Cardiac arrest remains the leading cause of death in Europe [1]. Without treatment, the cardiac arrest survival rate declines by 5.5 % per minute [2]. Early and effective cardiopulmonary resuscitation (CPR) can improve patient prognosis [1]. However, in reality CPR quality is reported to be poor even for health-care professionals [3]. There-fore, it is essential that medical students learn CPR as part of their curriculum. Simulation training is able to improve student skills and might improve patient outcomes [4,5]. The time tutors can spend with students and the avail-ability of resuscitation simulators is limited. Therefore, understanding the impact of assigning a defined number of students to a tutor and simulator is vital. Problems associated with larger groups might be that the “teache