Prevalence of reflux oesophagitis in all subjects in each group, categorised by serum Helicobacter pylori antibody (HpAb) and pepsinogen level (PG), showed a gradually decreasing trend in the order of group A to group D (A), the exact opposite to the pattern presented by the increasing trend of gastric cancer (B). The odds ratios with 95% confidence intervals (OR (95% CI)) between adjacent groups, which may reflect the progress of gastric atrophy induced by H pylori infection, adjusted for sex and age using unconditional logistic regression models, were 0.58 (0.44-0.76; p<0.0001) for reflux oesophagitis and 2.3 (1.5-3.4; p<0.0001) for gastric cancer.