Table 2.

Chest compression effectiveness

	Baseline unaided	Smartwatch-based feedback device	Defibrillator-based feedback device
Depth effectiveness (%)
All	29.7 ± 27.4	68.4 ± 25.0†	N/A
IH rescuers	40.2 ± 27.4	75.4 ± 25.6†	73.8 ± 37.3
OH rescuers	35.9 ± 32.3	75.1 ± 17.4†	81.1 ± 31.4
Lay rescuers	13.0 ± 12.3	54.6 ± 27.4†	N/A
Rate effectiveness (%)
All	30.1 ± 41.0	87.5 ± 21.4†	N/A
IH rescuers	27.1 ± 43.9	94.5 ± 5.5†	60.7 ± 34.3‡
OH rescuers	57.1 ± 44.5	92.8 ± 9.5†	82.2 ± 31.9
Lay rescuers	6.2 ± 7.0	75.2 ± 33.5†	N/A

Data are reported as mean ± SD.

IH = in-hospital; N/A = not applicable; OH = out-of-hospital.

^†P < .05 between baseline unaided and smartwatch-based feedback device.

^‡P < .05 between smartwatch-based feedback device and defibrillator-based feedback device.