“…A few studies were qualitative (4.6%) ( 35 , 70 , 74 ) or longitudinal (6.1%) ( 45 , 59 , 65 , 72 ). Most studies had samples consisting in PWE (71%) ( 10 , 11 , 21 – 23 , 25 , 30 – 34 , 36 , 38 , 39 , 41 – 44 , 46 , 49 – 51 , 53 – 61 , 63 , 66 , 67 , 69 , 70 , 72 , 74 – 83 ), though some specifically gathered samples of PWE who were known to use cannabis (17%) ( 29 , 35 , 40 , 45 , 47 , 48 , 64 , 65 , 71 , 73 , 84 ), and others gathered samples of cannabis consumers, searching for PWE among these consumers (7.6%) ( 26 , 27 , 37 , 62 , 68 ). Only non-random sampling methods were used; most frequently, convenience sampling (53%) ( 21 , 24 , 27 , 29 , 31 – 33 , 35 – 37 , 40 , 41 , 43 – 45 , 48 , 50 , 52 – 55 , 61 , 62 ...…”