Allicin as add-on therapy for Helicobacter pylori infection: A systematic review and meta-analysis

Table 7 Results of quality assessment

Participants (stu-dies)	Risk of bias	Inconsistency	Indirectness	Imprecision	Publication bias	Overall quality of evidence
Eradication rate
867(8 studies)	Very serious1	No serious inconsistency	Serious2	No serious imprecision	Undetected	Very low12
Healing rate of ulcers
807(7 studies)	Very serious1	No serious inconsistency	No serious indirectness	No serious imprecision	Undetected	Low1
Total remission rate of ulcers
807(7 studies)	Very serious1	No serious inconsistency	No serious indirectness	No serious imprecision	Undetected	Low1
Side effect rate
549(5 studies)	Very serious1	No serious inconsistency	Serious3	No serious imprecision	Undetected	Very low13

¹We downgraded by two levels because all included studies did not state random method although declared to be randomized. What's more, blinding of patients was not mentioned in all included studies and we preferred to identify these studies as non-blindness;

²The present systematic review mainly aimed to assess the efficacy with eradication rate as primary outcome in patients with H. pylori infection. However, the participants of seven included studies (7/8, 87.50%) included patients with H. pylori infection combined with peptic ulcers. Such difference might be another origin of bias;

³The present systematic review mainly aimed to assess the safety of allicin among patients with H. pylori infection. However, four included studies (4/5, 80.00%) included patients with H. pylori infection combined with peptic ulcers. Such difference might be another origin of bias.