“…Four studies used a single-centre approach [ 35 , 37 , 41 , 59 ]. Multi-centre designs varied in eight studies with 2 to 10 EDs [ 28 , 31 , 34 , 36 , 39 , 51 , 57 , 58 ], nine studies with 11 to 20 EDs [ 21 , 29 , 30 , 38 , 43 , 50 , 53 , 55 , 56 ], and three studies with 112 to 168 EDs [ 27 , 49 , 52 ]. Fifteen studies did not provide information on the number of surveyed EDs [ 22 – 26 , 32 , 33 , 40 , 42 , 44 – 48 , 54 ].…”