Fig. 2
Assessment of the standardisation for compression depth by the tutor. a. Correct compression depth: Median (Q25–Q75): 55 (55–60) mm, n = 51; incorrect compression depth: 30 (30–40) mm, n = 51; and compression rate (b). Correct frequency: 110 (105–110) bpm, n = 51 and incorrect frequency: 140 (135–140) bpm; n = 51 (Box-plot). Before every resuscitation scenario, the tutors performed the correct and the incorrect execution of the chest compressions separately. The hatched area highlights the reference range of the European Resuscitation Council Guidelines 2015 (50–60 mm and 100–120 bpm)