“…A summary of these groups is presented in Table 1 , while a condensed version of the data extraction table can be seen in Supplementary File 3 . There were thirteen RCTs [19] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] with random allocation and blinding maintained throughout; the remaining 60 studies were classified as observational studies [12] , [13] , [14] , [15] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , [56] , [57] , [58] , [59] , [60] , [61] , [62] , [63] , [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] , [72] , [73] , [74] , [75] , [76] , [77] , [78] , [79] , [80] , [81] …”