A critique of therapeutic trials in Helicobacter pylori-positive functional dyspepsia

Approximately 50% of patients with functional dyspepsia have Helicobacter pylori infection; it remains controversial whether this infection causes chronic symptoms, but rigorously conducted therapeutic trials should establish whether H. pylori plays a role in functional dyspepsia. The aim here was to determine whether the trials published over the past 10 years were methodologically adequate to establish a role for this infection in functional dyspepsia.

A broad-based Medline search to identify all treatment trials published between 1984 and 1993 was performed. All functional dyspepsia trials were systematically analyzed for potential design strengths and weaknesses.

Sixteen trials were included; 8 reported that anti-H. pylori therapy was efficacious and 8 failed to detect a statistically significant benefit. However, in all studies one or more serious methodological weakness was identified, including nonrandomized, non-placebo-controlled designs, lack of maintenance of blindness, application of inadequate outcome measures, failure to eradicate infection and follow up patients after therapy, and inadequate study power.

There is a pressing need for well-designed trials in H. pylori-positive dyspepsia, and practical suggestions are provided based on a review of the published literature.