Table 3. Differences of the outcomes between 1st chest compression cycle and 2nd to the last chest compression cycle.

Primary outcome	Group A	Group B	Group C	Group D	P-value
Difference of the sufficient CC ratio-%, median (IQR Q1-Q3)
Whole	-4 (-36-1)	-3 (-17-0)	0 (-5-4)	0 (-3-4)	<0.01
Male	0 (-9-3)	0 (-13-2)	0 (0–3)	0 (-1-9)	0.4
Female	-14 (-39-1)	-7 (-25-0)	0 (-16-12)	0 (-18-3)	0.03
Secondary outcome
Difference of the CC quickness-times/min, median (IQR Q1-Q3)
Whole	-6 (-10—1)	-4 (-10-1)	-5 (-9–1)	-1 (-5-2)	<0.01
Male	-5 (-8—2)	-4 (-8—2)	-5 (-6—1)	-2 (-7-2)	0.49
Female	-7 (-11—1)	-3 (-10—2)	-7 (-10—4)	0 (-4-2)	<0.01
Difference of the sufficient chest-recoil ratio-%,median (IQR Q1-Q3)
Whole	0 (-6-5)	0 (-1-9)	0 (-2-9)	0 (-4-6)	0.94
Male	0 (-9-9)	0 (-9-10)	0 (0–15)	1 (0–22)	0.68
Female	0 (-4-1)	0 (-1-1)	-1 (-6-1)	0 (-13-3)	0.85

CC, chest compression; IQR, interquartile range