What is the placebo effect versus the antibiotic effect size in trials on the treatment of dyspepsia?
Paul Moayyedi: These are placebo randomized controlled trials so there is an effect above placebo. The effect is small but it is high-quality evidence, because these are trials with a low risk of bias that have shown that among patients randomized to Helicobacter pylori eradication therapy there is a higher proportion of dyspepsia-free patients at 1 year than among those taking placebo. So there is a placebo effect.
In fact, in clinical practice when you have benefit, the majority of that benefit is just placebo and regression to the mean, but a small minority, maybe little less than 10%, is a true benefit of the antibiotics. That is what the randomized trials show us.