This is a trial in which we’re trying to do an intervention to reduce gastrointestinal bleeding on aspirin. People think of aspirin as causing ulcers but that’s really in high dose. At lower doses it has very little harmful effects on the stomach. What we think happens if someone has a bleeding ulcer is that the ulcer forms for another reason and that the role of aspirin is to increase the risk of bleeding. The other reason is a bacteria called Helicobacter pylori. So, on that basis, if we were to eradicate Helicobacter pylori then we would prevent bleeding peptic ulcer or reduce the incidence of bleeding peptic ulcer in patients on aspirin so that’s the rationale for the study.
What was the aim of the pilot study?
We were quite ambitious and we thought we would just enrol 10,000 patients but it was suggested we might need a pilot study to see if we could do that. So the main part of the pilot study was we enrolled 2,500 patients with just one nurse doing this over a six month period and we found it was very easy to identify patients through general practice records and patients were very keen and willing to come up and participate. So it gave us a lot of confidence in our methods.
How far along is the study?
We got funding from the HTA for this study. One ulterior motive was to find a way of doing very cheap trials to answer big questions that might not be susceptible to pharmaceutical funding. So this trial takes place in general practice, it’s all done with a single intervention with the patient and a follow-up with electronic records. We started recruiting to this trial about six weeks ago and we’re recruiting at the sort of rate that we need to do.
What is the trial design?
The trial design is that people who take aspirin come up and they are breath tested for Helicobacter pylori. A quarter of them are positive for the organism; we get an automated result which we check and then have a trial management system that gives out eradication treatment to patients who are randomised to active treatment or placebo to those who are not. This is done by post and, again, in our pilot study we found that worked and produced very high rates of eradication.
Were you surprised by the results of a 90% eradication?
Yes, we were quite surprised by this and I think we may have stumbled on an additional benefit of aspirin. It’s quite plausible from its mechanism of action that it might increase the access of antibiotics to H. pylori making it more effective. I think that hypothesis would be well worth testing in a controlled study.
Was this a national trial?
Yes, we’re working through the Comprehensive Local Research Network and the Primary Care Research Network and we have collaborators covering 49% of the country. So it’s very much a national study.
What do you think are the risks and benefits of aspirin?
I think the benefits are certainly there for vascular disease, although nowadays people are arguing that the benefits on various cancers, not just colorectal cancer, might be an even bigger effect. It’s extraordinary that this drug has so many effects. The downside is bleeding; one of the main causes of bleeding is bleeding peptic ulcer and that’s why we’re trying to do the study. We want to make aspirin safer and therefore more accessible to people by changing the risk-benefit ratio.
In low doses do you believe that aspirin causes bleeding?
No, I think it does. It doesn’t cause ulcers but if we get rid of the cause of the ulcer, the Helicobacter, then the bleeding won’t occur.
