. 2015 Oct 27;5:15635. doi: 10.1038/srep15635

Table 1. Characteristics of included randomized controlled trials.

Study/year	Region	Comparison	No. of patients	Mean age (y)	Cardiac etiology (%)	Witnessed cardiac arrest (%)	Bystander CPR before EMS arrival (%)	VF/VT as initial rhythm (%)	Adverse events
Perkins et al./2015¹¹	4 UK Ambulance Services	PD-CPR vs M-CPR	4471	Mechanical: 71.0 ± 16.3 Manual: 71.6 ± 16.1	Mechanical: 86 Manual: 87	Mechanical: 61 Manual: 62	Mechanical: 43 Manual: 44	Mechanical: 23 Manual: 22	No serious adverse events were reported
Rubertsson et al./2014⁹	4 Swedish, 1 British and 1 Dutch ambulance services	PD-CPR vs M-CPR	2589	Mechanical: 69.0 (16–100)^* Manual: 69.1 (15–99)^*	Mechanical: 65 Manual: 63	Mechanical: 66 Manual: 65	Mechanical: 57 Manual: 55	Mechanical: 29 Manual: 30	7 serious adverse events in the mechanical CPR group and 3 in the manual CPR group
Smekal et al./2011¹⁹	2 Swedish cities	PD-CPR vs M-CPR	148	Mechanical: 69 ± 16 Manual: 71 ± 16	Not reported	Mechanical: 68 Manual: 74	Mechanical: 34 Manual: 31	Mechanical: 27 Manual: 27	Not reported
Wik et al./2014¹⁰	3 US and 2 European sites	LDB-CPR vs M-CPR	4231	Mechanical: 65.7 ± 16.4 Manual: 65.6 ± 16.0	Mechanical: 100 Manual: 100	Mechanical: 37 Manual: 37	Mechanical: 47 Manual: 49	Mechanical: 21 Manual: 24	No significant difference between groups
Hallstrom et al./2006¹⁸	United States and Canada	LDB-CPR vs M-CPR	1071	Mechanical: 66.6 ± 15.6 Manual:66.2 ± 15.2	Mechanical: 85 Manual: 86	Mechanical: 44 Manual: 49	Mechanical: 32 Manual: 35	Mechanical: 31 Manual: 32	Not reported.

Data are presented as mean ± SD unless indicated otherwise.

UK, united kingdom; US, united states; CPR, cardiopulmonary resuscitation; PD-CPR, piston-driven CPR; LDB-CPR, load-distributing band CPR; M-CPR, manual CPR; EMS, emergency medical systems; VF, ventricular fibrillation; VT, ventricular tachycardia.

^*Mean (range).