Table 1.

Characteristics of studies included in the meta-analysis.

ID	Author year	Country	Type of control	Follow up times	Years of event rates	Follow-up (%)	Mean LVEF	Sex	Control n, age	Case n, age	RR (95% CI)
1	Hohnloser 2004	Germany	Pharmacologic therapy	30 months*	4 years	100.00%	0.28	F	80, 62.1 (10.6)	80, 61.5 (10.9)	1.00 (0.49, 2.04)
								M	252, 62.1 (10.6)	262, 61.5 (10.9)	1.14 (0.77, 1.69)
2	Wilcox 2014	USA	Pharmacologic therapy	24 months#	2 years	99.96%	0.25	F	1082, 69.3 (13.8)	604, 69.3 (13.8)	0.73 (0.55, 0.98)
								M	1985, 68.7 (12.8)	1955, 68.7 (12.8)	0.73 (0.57, 0.92)
3	Hernandez 2010	USA	Pharmacologic therapy	48 months#	3 years	100.00%	≤0.35	F	1797, 75.3 (5.6)	99, 74.3 (5.5)	0.58 (0.41, 0.83)
								M	2012, 75.3 (5.6)	277, 74.3 (5.5)	0.80 (0.63, 1.01)
4	Russo 2008	USA	Pharmacologic therapy	45.5 months*	5 years	100.00%	0.25	F	588, 60 (50, 67)		0.90 (0.56, 1.43)
							0.24	M	1933, 60 (52, 69)		0.71 (0.57, 0.88)
5	Zareba 2005	USA	Conventional therapy	20 months*	2 years	99.80%	≤0.30	F	73, 64 (11)	119, 64 (11)	0.57 (0.28, 1.18)
								M	417, 65 (10)	623, 65 (10)	0.66 (0.48, 0.91)
6	Russo 2004	USA	Pharmacologic therapy	39 months*	2 years	99.40%	≤0.40	F	34, NP	34, NP	1.38 (0.63, 2.99)
								M	319, NP	317, NP	0.72 (0.55, 0.95)
7	Albert 2008	USA	Pharmacologic therapy	29 months*	5 years	100.00%	0.22	F	69, 59.1	63, 59.1	1.14 (0.50, 2.64)
							0.21	M	160, 57.9	166, 57.9	0.49 (0.27, 0.90)

LVEF – left ventricular ejection fraction;

^*mean;

^#length;

F – female; M – male; NP – not provided.