“…[ 3 , 6 , 8 , 9 , 19 , 21 – 42 ] Nineteen of them are cross-sectional studies, [ 3 , 6 , 8 , 19 , 21 – 24 , 25 – 28 , 30 , 31 , 35 , 37 – 40 ] and the remaining 8 are case–control studies. [ 9 , 29 , 32 – 34 , 36 , 41 , 42 ] Serology was utilized as the detection method for H pylori in 14 studies, [ 8 , 9 , 21 , 23 , 25 – 27 , 31 – 35 , 38 , 39 ] pathology in 4, [ 3 , 22 , 40 , 42 ] urea breath test (UBT) in 4, [ 6 , 37 ] Campylobacter-like organism test (CLO) in 6, [ 19 , 24 , 30 , 36 ] and combining UBT and CLO in 2. [ 28 , 29 ] Gender and age are reported in 22 [ 3 , 6 , 8 , 9 , 19 , 21 – 30 , 34 – 40 ] and 27 [ 3 , 6 , 8 , 9 , 19 , 21 –…”