The review was based on seven randomised controlled trials (RCTs), providing data for eight comparisons with data from 538 patients.
Eradication rates.
H. pylori eradication was successful for 77.5% of the patients (95% CI: 74.0, 81.0; 8 parallel-group trials).
H2-receptor antagonist versus PPI.
The H. pylori eradication rate was 78.6% (95% CI: 73.6, 83.5) for PPI-treated patients and 76.5% (95% CI: 71.4, 81.5) for those treated with H2-receptor antagonists; the difference was not statistically significant. The differences in eradication rate between the two acid lowering drugs ranged from 1 to 20% in the individual studies, with varying advantages for both drug classes. The authors reported that the logistic regression showed no difference in the eradication rates with H2-receptor antagonists and PPIs (P>0.4), even when adjusting for the duration of therapy and the number of antibiotics.
One versus two antibiotics.
The average eradication rate was 70.4% (95% CI: 65.3, 75.6) for treatment protocols with one antibiotic (4 studies) and 86.5% (95% CI: 82.1, 90.8) for protocols with two antibiotics (4 studies); the difference was significant (P<0.001). The eradication rates varied widely in the studies with only one antibiotic; in the studies with two antibiotics, all the eradication rates were above 80%. The logistic regression showed a significant influence of the number of antibiotics on the eradication rate (P<0.0005). Within the two study groups, the difference in eradication rates due to the type of acid lowering drug was not significant.
Duration of therapy.
In the one study with a treatment duration of less than 10 days, the eradication rates were 92% (95% CI: 80.8, 97.8) for the PPIs and 86% (95% CI: 73.2, 94.2) for the H2-receptor antagonists; the difference was not significant. In the long- term therapy studies (7 comparisons), the average eradication rate was 75.5% for PPIs and 74.3% for H2-receptor antagonists (95% CI reported as 69.7, 81.2 for both means); the difference was not statistically significant.