Survival with a CPC score of 1 or 2 occurred in 98 ( 7.5 % ) vs 82 ( 6.4 % ) ( risk difference , 1.18 % ; 95 % CI , -0.78 % to 3.1 % ) at intensive care unit discharge , in 108 ( 8.3 % ) vs 100 ( 7.8 % ) ( risk difference , 0.55 % ; 95 % CI , -1.5 % to 2.6 % ) at hospital discharge , in 105 ( 8.1 % ) vs 94 ( 7.3 % ) ( risk difference , 0.78 % ; 95 % CI , -1.3 % to 2.8 % ) at 1 month , and in 110 ( 8.5 % ) vs 98 ( 7.6 % ) ( risk difference , 0.86 % ; 95 % CI , -1.2 % to 3.0 % ) at 6 months with mechanical CPR and manual CPR , respectively .