Boiron, the world’s largest manufacturer of homeopathic products, has recently been in the headlines more often and less favourably than their PR-team may have hoped for. Now they have added to this attention by publishing a large and seemingly impressive multi-national study of homeopathy.
Its objective was “to evaluate the effectiveness of homeopathic medicine for the prevention and treatment of migraine in children”. For this purpose, the researchers recruited 59 homeopaths from 12 countries who included into the study a total of 168 children with “definite or probable” migraine. The homeopaths had complete freedom to individualise their treatments according to the distinct characteristics of their patients.
The primary study-endpoints were the frequency, severity and duration of migraine attacks during 3 months of homeopathic treatment compared to the 3 months prior to that period. The secondary outcome measure was the amount of days off school. The results are fairly clear-cut and demonstrated that all of these variables improved in the period of homeopathic care.
This study is remarkable but possibly not in the way Boiron intended it to be. The first thing to notice is that each homeopath in this study barely treated 3 patients. I wonder why anyone would go to the trouble of setting up a multi-national trial with dozens of homeopaths from around the globe when, in the end, the total sample size is not higher than that achievable in one single well-organised, one-centre study. A multitude of countries, cultures and homeopaths is only an asset for a study, if justified through the recruitment of a large patient sample; otherwise, it is just an unwelcome source for confounding and bias.
But the main concern I have with this study lies elsewhere. Its stated objective was “…to evaluate the effectiveness of homeopathic medicines…” This aim cannot possibly be tackled with a study of this nature. As it stands, this study merely investigated what happens in 3 months while children receive 3 months of homeopathic care. The observed findings are not necessarily due to the homeopathic medicines; they might be due to the passage of time, the tender loving care received by their homeopaths, the expectation of the homeopaths and/or the parents, a regression towards the mean, the natural history of the (in some cases only “probable”) migraine, any concomitant treatments administered during the 3 months, a change in life-style, a placebo-effect, a Hawthorne-effect, or the many other factors that I have not thought of.
Edzard Ernst offers a much needed critique of the latest pro-homeopathy study from homeopathic pharmaceutical laboratory (apparently not a contradiction in terms!) Boiron. Expect to see this study quoted and hyped up by proponents of the air guitar of medicine.