Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Adverse effects
Systematic review	Number of people in analysis not reported	Proportion of people with adverse effects 21% with triple regimen with clarithromycin 500 mg twice daily (with proton pump inhibitor and amoxicillin) 22% with triple regimen with clarithromycin 250 mg twice daily (with proton pump inhibitor and amoxicillin) Absolute numbers not reported	P = 0.77		Not significant
Systematic review	Number of people in analysis not reported	Proportion of people with adverse effects 40% with triple regimen with clarithromycin 500 mg twice daily (with proton pump inhibitor and metronidazole) 30% with triple regimen with clarithromycin 250 mg twice daily (with proton pump inhibitor and metronidazole) Absolute numbers not reported	P <0.0001	Effect size not calculated	triple regimen with lower-dose clarithromycin (with metronidazole)
RCT	288 people with H pylori infection and peptic ulcers	Adverse effects (not specified) 67/143 (47%) with triple regimen with 200 mg clarithromycin twice daily (with omeprazole and amoxicillin) 76/145 (52%) with triple regimen with 400 mg clarithromycin twice daily (with omeprazole and amoxicillin)	Significance not assessed
RCT	377 people with either gastric or duodenal ulcers, all positive for H pylori	Adverse effects 47% with triple regimen with clarithromycin 200 mg twice daily (with lansoprazole and amoxicillin) 54% with triple regimen with clarithromycin 400 mg twice daily (with lansoprazole and amoxicillin)	Significance not assessed
RCT	100 people with H pylori infection and a healed peptic ulcer or non-ulcer dyspepsia	Adverse effects with 7-day triple regimen with clarithromycin 400 mg twice daily (with rabeprazole and amoxicillin) with 7-day triple regimen with clarithromycin 200 mg twice daily (with rabeprazole and amoxicillin)	Reported as not significant P value not reported		Not significant