“…Twenty two studies (40%) were assessed to have high risk of bias [ 22 , 23 , 25 , 27 , 30 – 32 , 34 , 39 – 45 , 48 – 52 , 58 , 66 ], eight (15%) moderate [ 24 , 26 , 37 , 53 , 57 , 62 , 65 , 67 ] and 25 (45%) low risk of bias [ 10 – 12 , 19 , 20 , 28 , 29 , 33 , 35 , 36 , 38 , 46 , 47 , 54 – 56 , 59 – 61 , 63 , 64 , 68 – 72 ]. Two hundred and nineteen symptoms were reported across the 55 studies.…”