“…Overall, seven systematic reviews were assigned a moderate rating for overall confidence in review results (more than one non-critical weakness but no critical flaws) [ 15 , 40 , 42 , 45 , 47 – 49 ], four a low rating (one critical flaw – study selection not in duplication or failure to consider risk of bias for interpretation) [ 17 , 41 , 43 , 46 ], and one a critically low rating (more than one critical flaw) [ 44 ]. Almost all included systematic reviews met the requirements for defining an appropriate research question ( n = 12) [ 15 , 17 , 40 – 49 ], search strategy ( n = 11) [ 15 , 17 , 40 – 43 , 45 – 49 ], study selection ( n = 11) [ 15 , 17 , 40 – 45 , 47 – 49 ], risk of bias assessment ( n = 11) [ 15 , 17 , 40 – 43 , 45 – 49 ], explanation of heterogeneity in analyses ( n = 9) [ 15 , 17 , 40 – 42 , 45 , 46 , 48 , 49 ], and declaring sources of conflicts of interest ( n = 12) [ 15 , 17 , 40 – 49 ]. Most systematic reviews failed to explain their selection of the study designs for inclusion ( n = 11) [ 15 , 17 , 40 – 42 , 44 – 49 ], declare sources of funding for studies included in the review ( n = 11) [ 15 , 40 – 49 ] and/or carry out an adequat...…”