The compression-only CPR group was superior to the conventional CPR group regarding the proportion of appropriate chest compression ( mean SD = 59.8 % 40.0 % vs. 46.3 % 28.6 % ; p = 0.036 ) and the number of appropriate chest compressions ( mean SD = 119.5 80.0 vs. 77.2 47.8 ; p = 0.001 ) .