“…A search update to 20 May 2015 was carried out to identify newly relevant citations. Overall, this search produced 947 articles, 18 of which met the selection criteria (four RCT and 14 meta-analyses of RCT) (Abu Hashim et al, 2015;Cassina et al, 2014;Costello et al, 2006;Creanga et al, 2008;Hamed et al, 2010;Hosseini et al, 2013;Johnson, 2011;Karimzadeh and Javedani, 2010;Misso et al, 2013;Palomba et al, 2004Palomba et al, , 2009aPalomba et al, , 2009bPalomba et al, , 2013Palomba et al, , 2014Siebert et al, 2006Siebert et al, , 2012Tang et al, 2012;Tso et al, 2014). A flow diagram of the study is presented in Figure 2.…”