Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Eradication rates
Systematic review	2862 people 18 RCTs in this analysis	Eradication rates 1174/1456 (81%) with nitroimidazole-based regimens 1133/1406 (81%) with amoxicillin-based regimens	OR 1.00 95% CI 0.83 to 1.22 Significant statistical heterogeneity among RCTs (P = 0.14; statistical heterogeneity defined by the review as significant if P <0.2)		Not significant
Systematic review	893 people 7 RCTs in this analysis	Eradication rates 360/443 (81%) with amoxicillin-based regimens containing lower-dose clarithromycin (250 mg twice daily) 388/450 (86%) with nitroimidazole-based regimens containing lower-dose clarithromycin (250 mg twice daily)	Peto OR 0.68 95% CI 0.48 to 0.98	Small effect size	nitroimidazole-based regimens
RCT 3-armed trial	120 people with H pylori infection and dyspeptic symptoms or a history of peptic ulcer	Eradication rates 83% with 7-day metronidazole-based regimen (containing omeprazole plus clarithromycin) 92% with 7-day amoxicillin-based regimen (containing omeprazole plus clarithromycin) Absolute numbers not reported	Significance not assessed
RCT	People with H pylori infection and active peptic ulcers or a history of peptic ulcer	Eradication rates 73%, 95% CI 65% to 81% with metronidazole-based regimen 65%, 95% CI 57% to 75% with amoxicillin-based regimen Absolute numbers not reported	Significance of between-group difference not assessed
RCT	People with H pylori infection and active peptic ulcers or a history of peptic ulcer	Eradication rates 81%, 95% CI 73% to 88% with metronidazole-based regimens 65%, 95% CI 56% to 73% with amoxicillin-based regimens Absolute numbers not reported	Significance of between-group difference not assessed