“…The included studies comprised seven RCTs [ 22 , 23 , 26 , 29 , 35 , 39 , 43 ] and seven cohort studies [ 21 , 24 , 31 , 34 , 37 , 41 , 44 ]. The remaining were cross-sectional [ 4 ], [ 27 , 32 , 36 , 42 ] non-randomised experimental [ 2 ], [ 25 , 40 ] case–control [ 2 ], [ 28 , 45 ] qualitative [ 2 ], [ 30 , 33 ] case series [ 1 ] [ 46 ] and diagnostic accuracy studies[ 1 ] [ 38 ]. Half of the studies were conducted in the USA [ 21 , 22 , 24 , 26 – 28 , 32 , 33 , 36 , 37 , 40 – 42 , 46 ].…”