Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Adverse effects
RCT	48 people with persistent H pylori infection after treatment with a triple regimen	Adverse effects 84% with quadruple regimen 82% with triple regimen Absolute numbers not reported	P = 0.85		Not significant
RCT	84 people with persistent H pylori infection after treatment with a metronidazole-based triple regimen	Mild or moderate adverse effects 45% with quadruple regimen 66% with triple regimen Absolute numbers not reported