Editor,—I read with interest the results reported by Blum et al((2000) Gut 47:473–80; OpenUrlCrossRefPubMedWeb of Science) and the editorial which accompanied this article by McColl ((2000) Gut 47:461–4; OpenUrlAbstract/FREE Full Text). Professor McColl argues that the greater response to acid suppression observed in theHelicobacter pylori positive compared with the negative subjects in the Blum trial resulted from a lack of blinding of the investigators and the presence of an incentive for categorising H pylori positive subjects as non-responders. In support of this argument, he cites pooled data from two large randomised controlled trials (BOND and OPERA)1comparing omeprazole 20 mg, 10 mg, and placebo where overall no significant relationship between H pyloristatus and symptom relief was observed. However, there may be other explanations for the results observed by Blum et al.

We have previously reported in pooled data from the BOND and OPERA trials that in the H pylori positive group, 43% on omeprazole 20 mg had complete relief of dyspeptic symptoms (by intention to treat) compared with 35% in H pylori negative patients (versus 34% and 24% on placebo, respectively).1 Hence there was a small therapeutic gain observed in H pylori positive patients receiving omeprazole 20 mg versus those who were H pylori negative although the differences were not statistically …