Table 7.
Results of quality assessment
Participants (stud-ies) | 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 |
We 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;
The 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;
The 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.