“…Seven studies [ 31 , 32 , 36 , 39 , 58 , 65 , 74 ] scored 1 point because of statistical differences in the most or second-most important factors. Forty-five studies [ [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , 33 , 34 , 37 , 38 , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [53] , [54] , [55] , [56] , [57] , [59] , [60] , [61] , [62] , [63] , [64] , [67] , [68] , [69] , [70] , [71] , [72] , [73] , 75 , 76 ] scored 0 point in view of the lack of control over the most or second-most important factors in the comparability domain.…”