“…Where reported, public participant numbers ranged from 4 [ 83 ], to an estimated 1200 [ 84 ], though no numbers were given in 13 articles (14.0%) [ 45 , 47 , 49 , 58 , 69 , 72 – 74 , 77 , 85 – 88 ], and incomplete or estimated numbers were provided in a further 25 (26.9%) [ 40 , 43 , 44 , 50 , 51 , 56 , 57 , 61 – 63 , 66 , 76 , 82 , 84 , 89 – 99 ]. Some authors provided demographic data of public participants, such as age, gender, medical condition and/or race, however, there was no detail provided in more than half of articles ( n = 52, 55.9%) [ 37 , 38 , 40 , 41 , 43 – 51 , 55 , 58 , 59 , 61 , 63 , 66 , 68 , 69 , 71 – 74 , 77 , 79 , 81 – 88 , 93 , 95 – 110 ]. There were no studies where IAP2 public involvement level was rated as ‘Inform’, or ‘Empower’.…”