Jun 02 2014

The Clinical Evidence for Homeopathy

Dana Ullman is a notorious apologist for homeopathy. He has a reputation, at least among skeptics, for cherry picking data and making dubious arguments – whatever it takes in order to defend his beloved homeopathy. He then tops it off by accusing skeptics of being closed-minded for not accepting his drivel.

An article of his recently popped up on the Skeptic subreddit (posted by rzeczpospolita) with the challenge, “Countless scientific studies showing that homeopathy works. Or are you “skeptics” too closed minded to accept this fact?”

The article is too long to deconstruct in one blog post, so I will focus on the key claim – that clinical evidence demonstrates that homeopathy works. His primary piece of evidence is this:

In 1991, three professors of medicine from the Netherlands, none of them homeopaths, performed a meta-analysis of 25 years of clinical studies using homeopathic medicines and published their results in the British Medical Journal. This meta-analysis covered 107 controlled trials, of which 81 showed that homeopathic medicines were effective, 24 showed they were ineffective, and 2 were inconclusive.

This is the study. While the article itself is not dated, it does mention in the body that it is a reprint from 1995. Ullman appears to have posted the article in 2010 without updating the information. Apparently he thinks that a review from 23 years ago is still relevant.  When I look for systematic reviews to help me understand the current state of research on a topic, I get concerned if I am going back more than 3 or 4 years.

He then further cherry picked from the statements the authors made to give what is, in my opinion, a false impression of their conclusion. Ullman gives this quote:

“The evidence presented in this review would probably be sufficient for establishing homeopathy as a regular treatment for certain indications.”

Here is the actual bottom-line conclusion from the abstract:

“At the moment the evidence of clinical trials is positive but not sufficient to draw definitive conclusions because most trials are of low methodological quality and because of the unknown role of publication bias. This indicates that there is a legitimate case for further evaluation of homoeopathy, but only by means of well performed trials.”

They concluded the evidence was not sufficient, and that more research was needed. They specifically pointed out the unknown role of publication bias.

Let’s take a look at more recent systematic reviews of the clinical evidence. The most recent and thorough was conducted for the Australian government. This is a 2013 report (a bit more up to date) which concluded:

“There is a paucity of good-quality studies of sufficient size that examine the effectiveness of homeopathy as a treatment for any clinical condition in humans. The available evidence is not compelling and fails to demonstrate that homeopathy is an effective treatment for any of the reported clinical conditions in humans.”

Most of the evidence is crap, but what evidence we do have does not support the use of homeopathy for any condition. There is also a systematic review of systematic reviews by Edzard Ernst, which concluded:

“The findings of currently available Cochrane reviews of studies of homeopathy do not show that homeopathic medicines have effects beyond placebo.”

This review is from 2010, so it is already getting a bit long in the tooth, but nothing has changed since then.

A systematic review in Belgium published in 2012 had the same conclusion:

“The Belgian Health Care Knowledge Centre (KCE) has reviewed the evidence on homeopathy up until 2010. The indications for which homeopathy was tested were diverse. Most of the trials analysed were deemed of mediocre quality.
There was no evidence of any homeopathic treatment being more effective than the placebo effect.”

The British government also had experts review the evidence for homeopathy. Their 2009-2010 report concludes that there is no evidence for the efficacy of homeopathy. They further concluded that proponents of homeopathy choose to rely on a “selective” approach to the evidence.

Ullman did write favorably of a Swiss report on homeopathy from 2011. If you read deep into the Swiss report, however, it also concluded that the evidence does not justify rejecting the null-hypothesis for homeopathic treatment for anything. But then they argue that we should rely more on pragmatic studies rather than those pesky efficacy trials which are stubbornly negative.

An excellent review of the Swiss report by David Shaw concludes:

This paper analyses the report and concludes that it is scientifically, logically and ethically flawed. Specifically, it contains no new evidence and misinterprets studies previously exposed as weak; creates a new standard of evidence designed to make homeopathy appear effective; and attempts to discredit randomised controlled trials as the gold standard of evidence. Most importantly, almost all the authors have conflicts of interest, despite their claim that none exist. If anything, the report proves that homeopaths are willing to distort evidence in order to support their beliefs, and its authors appear to have breached Swiss Academies of Arts and Sciences principles governing scientific integrity.

Conclusion

There has been a great deal of clinical studies into the efficacy of homeopathy, covering decades of research. From this research we can conclude that most of the studies are of low quality. However, from those studies of sufficient quality to draw any conclusions it is clear that homeopathic potions do not work for any indication.

Homeopathy, put simply, does not work.

Multiple independent bodies have reviewed this research and come to the same conclusion. They have allowed homeopaths to have their say and make their best case, and that case is unconvincing.

They further conclude that homeopaths cherry pick and distort the evidence in order to make their case.

In this article Dana Ullman has failed to provide any convincing evidence for the efficacy of homeopathy, but he has provided yet more evidence to support that latter conclusion – you have to be highly selective and biased in your view of the clinical evidence in order to come to the conclusion that homeopathy works – because it doesn’t.

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