“…Two studies were conducted in Turkey [ 34 , 58 ], 1 in the USA [ 57 ], 1 in Korea [ 52 ], and the remaining 51 in China [ 14 , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [53] , [54] , [55] , [56] , [59] , [60] , [61] , [62] , [63] , [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] , [72] , [73] , [74] , [75] , [76] , [77] , [78] , [79] , [80] , [81] , [82] , [83] , [84] , [85] , [86] , [87] ]. Three studies were prospective [ 42 , 53 , 68 ], 47 retrospective [ [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] ...…”