“…Of the included studies, 21 (58%) had extractable data only for influenza-associated hospitalisation [ 14 – 18 , 22 , 23 , 31 , 33 , 34 , 38 – 44 , 46 – 49 ] and five (14%) had extractable data only for influenza-associated mortality [ 21 , 29 , 30 , 35 , 36 ]. There were 10 studies (28%) with extractable data for both hospitalisation and mortality [ 19 , 20 , 24 – 28 , 32 , 37 , 45 ]. Nearly three quarters of included studies (n = 26, 72%) analysed hospitalisations and/or deaths during the 2009pH1N1 [ 17 – 20 , 25 – 27 , 29 – 33 , 35 – 41 , 44 – 49 ], while seven (19%) analysed hospitalisations and/or deaths from seasonal influenza [ 14 , 15 , 22 , 23 , 34 , 42 , 43 ] and four (11%) covered both seasonal and pandemic periods [ 16 , 21 , 24 , 28 ].…”