Clinical Efficacy of Extracorporeal Cardiopulmonary Resuscitation for Adults with Cardiac Arrest: Meta-Analysis with Trial Sequential Analysis

Table 2

Results of subgroup analysis based on different standards.

Characteristics	Survival outcome					Neurologic outcome
	N	RR(95%CI)	P value for heterogeneity	I^2 (%)	P values Between subgroups	N	RR(95%CI)	P value for heterogeneity	I^2(%)	P values between subgroups
All	11	1.60(1.25-2.06)	0.16	30		7	2.69(1.63-4.46)	0.08	46
Nation					0.91					0.21
Eastern countries	10	1.63(1.23-2.13)	0.11	37		5	2.23(1.52-3.27)	0.02	29
Western countries	1	1.56(0.74-3.27)	NA	NA		2	3.66(1.85-7.25)	0.23	81
Propensity score matching					0.97					0.008
Yes	8	1.65(1.14-2.40)	0.06	49		5	1.87(1.29-2.71)	0.48	0
No	3	1.67(1.19-2.34)	0.96	0		2	6.97(2.89-16.79)	0.63	0
Presumed aetiology					0.31					0.74
Cardiac-origin	6	1.37(1.06-1.76)	0.44	0		4	2.57(1.74-3.82)	0.03	65
Not stated	5	1.80(1.13-2.89)	0.08	52		3	2.58(1.39-4.82)	0.28	21
Witnessed arrest					0.03					0.23
Witnessed	6	2.22(1.57-3.14)	0.42	0		3	2.02(1.21-3.39)	0.65	0
Not stated	5	1.26(1.01-1.59)	0.35	10		4	4.08(1.46-11.37)	0.02	70
Study quality					0.20					0.43
High quality	7	1.90(1.39-2.59)	0.15	37		4	2.20(1.33-3.62)	0.46	0
Low quality	4	1.32(1.04-1.68)	0.39	1		3	3.65(1.15-11.54)	0.01	77

Abbreviations: N= number of participants, NA=not application, RR= relative risk, and CI=confidence interval;