When I look at the comments to my last two posts about homeopathy, I begin to worry about the sanity of some of the pro-homeopathy commentators. I find it hard to spot anything with substance among all the insults.
However, there might be one exception, and that is the repeated claim that an acclaimed scientist, Professor Robert Hahn, has effectively invalidated my views on homeopathy. As this is a potentially important argument, I feel obliged to provide an explanation. Here it is.
In 1997 Linde et al published their now famous meta-analysis of clinical trials of homeopathy which concluded: ‘The results of our meta-analysis are not compatible with the hypothesis that the clinical effects of homeopathy are completely due to placebo. However, we found insufficient evidence from these studies that homeopathy is clearly efficacious for any single clinical condition. Further research on homeopathy is warranted provided it is rigorous and systematic.’
As this paper had several limitations, the authors conducted a re-analysis which is unfortunately rarely cited by homeopaths. Linde et al stated in their re-analysis of 2000: ‘There was clear evidence that studies with better methodological quality tended to yield less positive results.’ It was this phenomenon that prompted me and my colleague Max Pittler to publish a letter to the editor which has now become the stone of homeopathic contention and fury.
One blog post even goes as far as asking the question: did Professor Ernst sell his soul to Big Pharma? It continues as follows:
Edzard Ernst is an anti-homeopath who spent his career attacking traditional medicine. In 1993 he became professor of complementary medicine at the University of Exeter. He is often described as the first professor of complementary medicine, but the title he assumed should have fooled no one. His aim was to discredit medical therapies, notably homeopathy, and he then published some 700 papers in ‘scientific’ journals to do so.
Now, Professor Robert Hahn, in his blog, has made an assessment of the quality of his work… In the interests of the honesty and integrity in science, it is an important assessment. It shows, in his view, how science has been taken over by ideology (or as I would suggest, more accurately, the financial interests of big corporations, in this case Big Pharma). The blog indicates that in order to demonstrate that homeopathy is ineffective, over 95 per cent of scientific research into homeopathy has to be discarded or removed!
So for those people who, like myself, cannot read the original German, here is an English translation of the blog.
‘I have never seen a science writer so blatantly biased as Edzard Ernst: his work should not be considered of any worth at all, and discarded,’ finds Sweden’s Professor Robert Hahn, a leading medical scientist, physician, and professor of anaesthesia and intensive care at the University of Linköping, Sweden.
Hahn determined therefore to analyse for himself the ‘research’ which supposedly demonstrated homeopathy to be ineffective, and reached the shocking conclusion that:
‘Only by discarding 98 per cent of homeopathy trials and carrying out a statistical meta-analysis on the remaining two per cent negative studies can one “prove” that homeopathy is ineffective.’
In other words, all supposedly negative homeopathic meta-analyses which opponents of homeopathy have relied on are scientifically bogus…
But who is Professor Hahn, and what article of mine is he criticising? Let me try to answer these questions in turn.
Who is Professor Hahn?
Here I can rely on a comment posted on my blog by someone who can read Swedish:
A renowned director of medical research with well over 300 publications on anaesthesia and intensive care and 16 graduated PhD students under his mentorship, who has been leading a life on the side, blogging and writing about spiritualism, and alternative medicine and now ventures on a public crusade for resurrecting the failing realm of homeopathy. Unbelievable!
I was unaware of this person before, even if I have lived and worked in Sweden for decades.
I have spent the evening looking up his net-track and at his blog at roberthahn.nu (in Swedish). I will try to summarise some first impressions:
Hahn is evidently deeply religious [and] confident that there is more to this world than what can be measured and sensed. In effect, he seems to believe that homeopathy (as well as alternative medical methods in general) must work because there are people who say they have experienced it and denying the possibility is akin to heresy (not his wording but the essence of his writing).
He has, along with his wife, authored at least three books on spiritual matters with titles such as (my translations) Clear Replies From the Spiritual World and Connections of Souls.
He has a serious issue with sceptics and goes on at length about how they are dishonest bluffers who wilfully cherry-pick and misinterpret evidence to fit their preconceived beliefs.
He feels that desperate patients should generally be allowed the chance that alternative methods may offer.
He believes firmly in former-life memories, including his own, which he claims he has found verification for in an ancient Italian parchment.
His main arguments for homeopathy are Claus Linde’s meta analyses and the sheer number of homeopathic research that he firmly believes shows it being superior to placebo, a fact that (in his opinion) shows it has a biological effect. Shang’s work from 2005 he dismisses as seriously flawed.
He also points to individual research like this as credible proof of the biologic effect of remedies.
He somewhat surprisingly denies recommending homeopathy despite being convinced of its effect and maintains that he wants better, more problem-oriented and disease-specific studies to clarify its applicability (my interpretation).
If it weren’t for his track record of genuine, acknowledged medical research and him being a renowned authority in a genuine, scientific medical field, this man would be an ordinary, religiously devout quack.
And what about the article that Hahn refers to?
It was a mere letter to the editor published in the Journal of Clinical Epidemiology commenting on the above-mentioned re-analysis which Linde et al had published in the same journal. As its text is not available online, I repeat the crucial parts of it here:
In an interesting re-analysis of their meta-analysis of clinical trials of homeopathy, Linde et al conclude that there is no linear relationship between quality scores and study outcome. We have simply re-plotted their data and arrive at a different conclusion. There is an almost perfect correlation between the odds ratio and the Jadad score between the range of 1-4… [Some technical explanations follow. Subsequently, we concluded that…] Linde et al can be seen as the ultimate epidemiological proof that homeopathy is, in fact, a placebo.
And that is, as far as I can see, what all the fuss is about. Do you now understand why I worry about the sanity of these homeopaths?
Edzard Ernst, emeritus professor at the University of Exeter, is the author of A Scientist in Wonderland and the awardee of the John Maddox Prize 2015 for standing up for science. He blogs at edzardernst.com.