“…Most articles described a single health research study although four articles [ 39 , 46 , 55 , 56 ] described multiple health research studies within which PPIE was embedded. The most commonly reported research designs were qualitative (n = 20) [ 13 , 18 , 20 – 22 , 36 , 41 – 43 , 45 , 48 , 50 , 51 , 53 , 54 , 57 – 59 , 63 , 65 ] and mixed-methods (n = 11) [ 14 , 35 , 39 , 40 , 46 , 47 , 55 , 60 , 64 , 66 , 67 ]; of these studies, five (qualitative n = 1, and mixed methods n = 4) drew on a participatory methodology [ 35 , 36 , 41 – 43 ]. The remaining studies included randomised control trials (n = 4) [ 19 , 37 , 38 , 44 ], case study (n = 2) [ 49 , 52 ] or systematic review (n = 1) [ 61 ].…”