“…And OR values were < 1 in 7 [ 15 , 19 , 33 , 34 , 37 , 46 , 49 ] of these 8 literatures. On the other hand, 7 [ 12 , 16 , 18 , 25 , 29 , 36 , 57 ] of 13 Asian studies [ 12 , 16 , 18 , 25 , 29 , 30 , 36 , 38 , 40 , 43 , 50 , 52 , 57 ] reported that patients with GI symptoms were older, and OR values were > 1 in 6[ 12 , 16 , 25 , 29 , 36 , 57 ] of these 7 studies. It turns out that the studies carried out in different locations vary in the characteristics of included patients, especially in the age of patients with/without GI symptoms.…”