Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Regression of gastric atrophy
RCT 4-armed trial	852 people with gastric atrophy or intestinal metaplasia found at screening endoscopy	Atrophy with H pylori eradication treatment with no H pylori eradication treatment Absolute results not reported	RR 4.8 95% CI 1.6 to 14.2 Result calculated by multivariate modelling	Moderate effect size	H pylori eradication treatment
Regression of intestinal metaplasia
RCT 4-armed trial	852 people with gastric atrophy or intestinal metaplasia found at screening endoscopy	Intestinal metaplasia with H pylori eradication treatment with no H pylori eradication treatment Absolute results not reported	RR 3.1 95% CI 1.0 to 9.3 Result calculated by multivariate modelling	Moderate effect size	H pylori eradication treatment