“…All study characteristics are detailed in the supplementary material (Tables DS2 and DS3). Of the 30 studies, 13 were conducted in the UK, 27 , 28 , 30 , 33 , 36 , 37 , 41 , 44 , 46 , 47 , 49 , 51 – 53 ten in the USA, 20 , 29 , 31 , 32 , 34 , 38 , 39 , 43 , 48 , 50 four in Canada, 35 , 40 , 42 , 55 and one each in Norway 45 and Sweden 54 . Sixteen studies examined data from only patients' perspectives, 28 , 29 , 32 , 33 , 37 , 39 – 43 , 45 , 46 , 49 , 50 , 53 , 55 six from only health professionals' perspectives, 30 , 34 , 35 , 47 , 51 , 52 , 54 and only one from carers' perspectives.…”