Table 1.

Study ID	Type of Study	Age Mean±SD	Sample Size	Longest follow up	Risk difference between QL versus BL (95% CI)
Arias et al 2012	Prospective Observational	65.6 ± 9.9	42	9 months	-0.05 [-0.20, 0.11]
Forleo et al 2012	Retrospective	68.3±10.7	45	6 months	-0.23 [-0.43, -0.03]
Corbisiero et al 2014	Retrospective	No data	79	3 months	-0.02 [-0.09, 0.04]
Dhillion et al 2014	Retrospective	71±8	29	6 months	0.00 [-0.12, 0.12]
MORE-CRT 2014	Prospective randomized	68±10	1,068	6 month	-0.03 [-0.06, 0.01]
Turakhia et al 2014	Prospective Observational	69.8±11.3	24,293	12 months	-0.01 [-0.02, -0.01]
Forleo et al 2015	Prospective Observational	70.3±9.2	418	39 months	-0.05 [-0.10, -0.01]
Behar et al 2015	Prospective Observational	68.4 ± 0.55	721	60 months	-0.08 [-0.12, -0.05]