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Saturday, 12 September 2015

The contribution of Professor Edzard Ernst to disinformation about Homeopathy

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 published some 700 papers in 'scientific' journals to do so.

Now, Professor Robert Hahn, a leading medical scientist, physician, and Professor of Anaesthesia and Intensive Care at the University of Linköping, Sweden, has made an assessment of the quality of his work. It can be read, in German, here:

"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% 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.

Studies depicting homeopathy as ineffective are bogus
Professor Hahn has published over 300 scientific articles in the fields of anesthesia and intensive care, and has received several research awards. Hahn had not previously come into contact with homeopathy, but his curiosity was aroused by a highly emotional, remarkably unscientific, television debate against homeopathy, apparently organized by the anti-homeopathy campaigning group 'Vetenskap och Folkbildning' or VOF [translates into English as 'Science and Education'] One teenager after another said that there were no scientific studies that could prove that homeopathy works, and that Homeopathy had been shown to be one big 'bluff'.

(Interjection: this organisation is probably the equivalent of 'Sense about Science' in Britain).

Professor Hahn clearly saw that those teenagers could not possibly have the necessary skills, knowledge and maturity to even read, let alone understand, the relevant scientific literature, and that all they were doing was repeating to order VoF's anti-homeopathy propaganda.

Hahn determined therefore to analyze for himself the 'research' which supposedly demonstrated homeopathy to be ineffective, and reached the shocking conclusion that:

          "only by discarding 98% of homeopathy trials and carrying out a statistical meta-analysis on the remaining 2% 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.

The evaluation criteria of medical treatment changed in the mid-1990s. It had previously been held that one should understand the mechanism why a treatment works before being able to accept it. This criterion, however, leads to problems. Many treatments, whose mode of action is still unknown, are in fact in use today in hospitals with success. Nitrous oxide, commonly used during the birth, is one such example (anaesthetics are another).

Medicine in the mid-90s moved over to the practical concept of "evidence-based", which implies that this was, or should have been, the method used for all the literature in the areas of systematic reviews or meta-analyzes. The question now asked was no longer

     "Do we understand the basic principles of treatment?"
     "Does the treatment work, or not?"

The removal of any requirement to demonstrate a mechanism makes it a major problem for academics to dismiss alternative therapies.

Klaus Linde's Article 
Klaus Linde's meta-analysis from 1997 [i] is the first and most honest writing in the field of homeopathy. Linde found an odds ratio of 2.45 and a 2.05 to 2.93 of CI, i.e., a significant result showing a beneficial effect of homeopathy compared to placebo.

This result is based on 89 studies and, interestingly, Linde added in a summary that the results shows how effective homeopathy is in various diseases. Linde's study aroused understandable sensation in the academic world. Then followed a counter current of articles that evidently tried to refute the results.

The first criticism was the quality of the study, which can be separated into so-called Jadad scores. When they did this with Linde's 89 studies, there was a trend for the studies with a low Jadad to show a higher effect. Linde demonstrated [ii] however that the positive effects of homeopathy were increased, even at the highest Jadad score levels.

Edzard Ernst
This argument was not accepted by the anti-alternative-medicine activist Edzard Ernst, who was of the opinion that one should draw a line between all Jadad scores except for the highest, and from that calculate the theoretical effect of the best studies (see reference iii).

In my opinion, this is completely insane, because you thereby replace real data with virtual (i.e. theoretically calculated) data.

In his 2002 paper [iv], "A systematic review of Systematic Reviews", Ernst oscillates, for example, between rejection of articles which show specific effects on diseases, whilst in other instances he rejects articles if they do not show specific effects. I've never seen a science writer so blatantly biased as Edzard Ernst.

Cucherat's "Type II error"
Cucherat [v] "Evidence  of clinical efficacy Homeopathy", is basically an honest writer who nevertheless, in contradiction of his own research results, ended in making great efforts to reject homeopathy as a treatment. Conventional meta-analytic statistics were not used in this case; instead, out of five possible analytic methods, Cucherat chose the method which would be the most unfavourable to homeopathy.

Furthermore Cucherat fell into using a technique that Edzard Ernst exploited in many studies, namely, to remove virtually any high-quality material. In the case of homeopathy, however, it was not enough to remove 90% of the studies originally envisaged for analysis: the homeopathic treatment continued to show itself as superior to placebo.

As the author proceeded to remove 95-98% of all studies, this naturally tilted the statistics. But at this point, Cucherat's analysis no longer showed that the method of treatment (homeopathy) is bad, but rather that his study lacked sufficient statistical material for analysis. One can say that the author has created a "type II error" deliberately.

I am highly critical of the several points given by Cucherat to justify his rejection of selected studies. Cucherat gives sometimes only marginal details that do not result in exclusion in non-homeopathic studies. First Cucherat removed from his evaluation 101 out of a total of 118 studies: homeopathy nevertheless remained in his analysis as being to a large extent effective. Even as he withdrew further studies and only 9 were left, homeopathy continued to show a statistically-safe beneficial effect.

As he removed yet another 4 studies, the statistics however began to falter and the risk that the effect of homeopathy versus placebo could be explained by chance was now 8.2 out of 100.

The conclusion? Cucherat says that homeopathy was not effective. As far as I am concerned, Cucherat is a coward. At the risk of destroying his career by telling the truth and being in loggerheads with organizations such as the VoF, he did not dare to publish what his material actually showed.

Shang et al's selection was equally crazy
The next meta-analysis was written by Shang et al and published in 1995 [vi]. Here, just like Cucherat, 96% of all studies were removed, but in this case the authors sadly failed to specify any reason for that at all.

They turned the odds ratio this way and that, until it resulted in the study showing that placebo was 13% more effective than homeopathy, even though the actual evidence showed the precise opposite: i.e., that homeopathy was 13% more effective than placebo. I must also point out that the authors with whom Shang worked had a few years earlier published a very negative article on homeopathy, which makes me doubt the objective starting point of this group.

(Ernst was later to testify to the UK House of Commons Science and Technology Committee that Shang was 'clearly devastating for homeopathy').

Who can you trust? We can begin by disregarding Edzard Ernst. I have read several other studies that he has published, and they are all untrustworthy. His work should be discarded.

Both Cucherat and Shang have deliberately created a "Type II error" by ignoring almost all actually existing published studies. The reason? Well, if they had included just a few more trials and had have been content to exclude "only" 90% of the documentation, it would have been found that homeopathy was more effective than placebo. And they surely didn't want that, right? So they simply excluded so much material that they created a "type II error". I assume that the authors had to find some trick to produce the results they wanted from the outset - namely, that homeopathy failed to produce any effect.

This maths game seems anything other than respectable. And yet these people could retain their academic purity, still welcome in the hallowed halls of science, and not at risk of being mocked or to be publicly ridiculed by organizations such as the VoF.

I am fascinated to see how much the scientific world is controlled by their ideologies.

In the case of homeopathy, one should stick with what the evidence reveals. And the evidence is that only by removing 95-98% of all studies is the effectiveness of homeopathy not demonstrable.

Homeopathy is clearly a taboo subject. If anything relates to homeopathy, you may not work with the search for, or evaluation of, evidence if you want to continue to be considered a good and serious scientist. This kind of fear should not exist in science. But it does exist, and is very striking".

[i] Linde K, Clausius N, Ramirez G, Melchart D, Eitel F, Hedges LV, Jonas WB. Are the clinical effects of homeopathy placebo effects? A meta-analysis of placebo-controlled trials. Lancet 1997; 350: 834–43.

[ii] Linde K, Scholz M, Ramirez G, Clausius N, Melcart D, Jonas WB. Impact of study quality on outcome in placebo-controlled trials of homeopathy. J Clin Epidemiol 1999;52:631–6.

[iii] Ernst E, Pittler MH. Re-analysis of previous meta-analysis of clinical trials of homeopathy. J Clin Epidemiol 2000;53:1188.

[iv] Ernst E. "A systematic review of systematic reviews of homeopathy" (Br J Clin Pharmacol 2002; 54: 577-582)

[v] Cucherat M, Haugh MV, Gooch M, Boissel J-P. Evidence for clinical efficacy of homeopathy. A meta-analysis of clinical trials. Eur J Clin Pharmacol 2000;56:27–33.

[vi] Shang A, Huwiler-Münterer K, Nartey L, Jüni P, Dörig S, Sterne JA, Egger M. Are the clinical effects of homeopathy placebo effects? Comparative study of placebo-controlled trials of homeopathy and allopathy. Lancet 2005;366:726–32.