Herpes and liquorice – a Tetley trial*

*Tetley tea bags – small, full of holes and don’t hold water.

I should state that I have no particularly reason to attack the Herpes Viruses Association and the rest of their website looks to be a helpful resource for their target market. That said…

I couldn’t help noticing some of their claims for A Double-blind Comparison of Liquorice-root Based Balm (Liquorice Balm) and Placebo Preparation – A Consumer Study. Perfect, I thought, an opportunity to flex my appraisal muscles. To be honest though it feels more like shooting fish in a barrel.

The trial

There were 37 patients recruited (by advertisement on the HVA website) who suffer from herpes in the mouth, genitals or anus. They were randomly given either liquorice balm or placebo blinded both to them and the trial organiser.

The placebo was designed to be as pleasant as possible so that users would not be able to distinguish it from the study treatment.

Very sensible – but according to their own data this would not appear to be completely the case.

Considering the overall number of subjects in the trail is just 37 it is slightly concerning that 6 of those 37 dropped out for various reasons. Once the veil of blinding was drawn back it turned out that all the dropouts had been placebo – was it that unpleasant? One did drop out for the reason that it made their symptoms worse and another because they were sure it was indeed placebo. Apparently 93.3% found the liquorice balm pleasant versus 77.8% of the placebo users. Is this significant? No, but the numbers involved in this study are utterly feeble and this is ultimately the critical weakness.

There are some concerns with the way this paper has been presented. I really don’t believe there is a place for the reporting of volunteers’ comments (aka testimonials) in a paper that purports to be presenting information in an objective double-blind placebo controlled trial. If the paper was setting out to explore opinions and views through qualitative methods, and if subject to appropriate analysis, this may be helpful but otherwise it smacks of science by anecdote.

The advert (with handy link) for liquorice balm at the bottom of the report does not fill me with joy either. Mind you, it is common to see Big Pharma adverts butted up against trials in the journals and the sellers of the liquorice cream sensibly do not make the same claims as the HVA.

Regarding the objective measurements relating to numbers and durations of attacks, let me quote:

The small sample size and high standard deviation makes the figures almost impossible to interpret statistically.

No, I would disagree – they are incredibly easy to interpret statistically – the liquorice cream doesn’t show any difference and further analysis ain’t worth much. What is almost impossible is the likelihood that this study was ever going to show a result. Don’t let that stop you though HVA:

I could go on. Suffice to say that I could not wholly subscribe to the authors’ view that this is a “well designed study which was carried out without any obvious bias”. I have no idea what the involvement of the patrons (Phil Hammond et al) was in this trial and whether they have approved any of the content. The use of their names on the bottom of the page (with an absolute epidemic of post-nominals) lends legitimacy to this study; legitimacy that is otherwise lacking.

Two more thoughts:

I also couldn’t help noticing the “Funding from the Department of Health” badge. Is this study a good way to spend the HVA’s funds or those of the taxpayer?

There is no mention of ethical committee approval for this trial – is it ethical to conduct trials with patient numbers so limited that there is almost no chance of showing a significant result?

Finally

The HVA website is full of sound sensible advice for those who live with herpes. Commissioning methodologically suspect trials and drawing spurious conclusions for products won’t do much to enhance their credibility.