“…Publications reported using varied sampling approaches including convenient sampling, [ 41 ] and opportunistic sampling [ 42 ], usually through routine health care [ 27 , 41 , 51 , 58 , 67 ]. However most papers reported purposeful sampling , [ 27 – 29 , 34 , 39 , 47 , 48 , 55 , 56 , 59 – 61 , 68 ] including through key community Elders and representatives [ 33 , 50 , 69 ].…”