“…Across studies there was a total of n = 3803 participants, including patients, informal carers and family members. Studies were mostly conducted in the USA ( n = 13) [ 29 , 40 , 42 , 44 , 54 , 55 , 59 , 61 , 65 , 67 – 69 , 72 ], Australia ( n = 11) [ 26 – 28 , 30 , 34 , 36 , 41 , 52 , 57 , 63 , 66 ], UK ( n = 7) [ 31 , 39 , 46 – 48 , 53 , 60 ], Sweden ( n = 4) [ 38 , 49 – 51 ], Canada ( n = 3) [ 32 , 35 , 45 ] and The Netherlands ( n = 2) [ 9 , 64 ] with one study undertaken each in Belgium [ 62 ], Italy [ 71 ], France [ 33 ], New Zealand [ 43 ], Norway [ 58 ], Qatar [ 56 ] and, Spain [ 70 ], and one study conducted across multiple European countries [ 37 ]. Key characteristics of included studies are outlined in Additional file 3 .…”