Study designs of evaluations included in the review
Randomised double-blind studies including at least 50 patients, with analysis of results based on intention to treat and completed by end of September 1992, were included.
Specific interventions included in the review
Omeprazole 20 mg once daily; ranitidine 150 mg twice daily or 300 mg at night; cimetidine 400 or 600 mg twice daily or 800 mg at night.
Participants included in the review
Patients with endoscopically confirmed duodenal ulcer (minimum initial size 5 mm diameter) treated initially for 2 weeks, with endoscopy and assessment of symptoms on day 15. If the ulcer remained unhealed, 2 weeks additional treatment followed by endoscopy on day 29. Patients with gastric ulcer (minimum initial size 5 mm diameter) and reflux oesophagitis (defined as presence of erosive or ulcerative lesions in the oesophageal mucosa) treated for 4 weeks, with endoscopy on day 29, and if unhealed, 4 weeks additional treatment with endoscopy on day 57.
Duodenal ulcer patients involved in the analysis:
1,748 treated with omeprazole in comparisons with ranitidine,
1,756 treated with ranitidine;
674 treated with omeprazole in comparisons with cimetidine; and
689 treated with cimetidine.
Gastric ulcer patients involved in the analysis:
374 treated with omeprazole in comparisons with ranitidine; and
369 treated with ranitidine.
189 Patients were involved in the study comparing omeprazole with cimetidine.
Of the reflux oesophagitis patients involved in the analysis,
465 were treated with omeprazole, and
470 with ranitidine.
A meta-analysis of adverse events (randomised double-blind studies of omeprazole versus ranitidine or cimetidine; n=5,281) was also reported.
Outcomes assessed in the review
The outcome was healing of lesions (defined as complete re-epithelialisation of all ulcer craters), as confirmed by endoscopy.
How were decisions on the relevance of primary studies made?
Two independent reviewers selected studies meeting the inclusion criteria, and resolved any disagreements by discussion.