“…A total of 52 studies reported numbers or percentages of patients retained at this step [ 8 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 34 , 36 , 40 , 41 , 42 , 43 , 46 , 56 , 58 , 65 , 68 , 69 , 72 , 73 , 74 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 95 , 96 , 97 , 98 , 99 ]. The majority of studies (32 studies, 62%) covering this step were longitudinal studies.…”