“…The majority of articled revised were studies conducted in the United States (12) [ 77 , 80 – 82 , 84 , 88 , 90 , 94 , 95 , 99 , 100 , 104 ], three were from Kenya [ 86 , 92 , 102 ] and three from South Africa [ 85 , 93 , 101 ]. Locations like China, the United Kingdom and Zambia had two studies included in this review [ 79 , 87 , 91 , 96 , 98 , 103 ] and, from the total of articles included, only one article was from Malaysia, Nigeria, Tanzania and Uganda [ 78 , 83 , 89 , 97 ].…”