Table 2.

Pooled risk ratios of mortality for ICD treatment cases vs. control group cases in the meta-analysis.

Total/subgroup	Category	No. of studies	RR (95% CI)	Heterogeneity test
				P	I2 (%)
Male
All studies		7	0.73 (0.66, 0.80)	0.217	27.7
Years of event rates	2–3 years	4	0.72 (0.64, 0.81)	0.674	0.0
	4–5 years	3	0.76 (0.51, 1.14)	0.039	69.3
Female
All studies		7	0.75 (0.63, 0.90)	0.306	16.3
Years of event rates	2–3 years	4	0.69 (0.56, 0.85)	0.222	31.7
	4–5 years	3	0.96 (0.68, 1.37)	0.883	0.0