The Cochrane collaboration is a highly regarded international association that seeks to provide the most up to date summary of the available evidence surrounding medical treatments. It does this by publishing systematic reviews of clinical studies authored by independent reviewers.
Earlier this week the Cochrane colloaboration published a review examining Homeopathic medicines for adverse effects of cancer treatments. The review looked at eight studies, considered relevant and of suitable quality, although in actual fact the studies could be subdivided further as they are addressing three different things. All were looking at the effectiveness of homeopathic treatments but three were concerned with alleviating the effects of radiotherapy, three alleviating the symptoms of chemotherapy and two allievating menopausal symptoms in women with breast cancer.
All of these studies were thus not looking at whether homeopathic treatments have any effect on cancer directly although unfortunately this connection will likely be drawn by many who see the headlines reporting this review. Instead, they were looking at whether homeopathic treatments could alleviate the side effects of two cancer treatments and menopausal symptoms in cancer sufferers better than a placebo treatment.
The results from the studies were not overwhelming. Four showed positive results and four showed negative results. On top of this only three of the studies were designated as being both of high quality and having a low risk of bias and from these three one was positive and two were negative. Furthermore, as a number of commentators pointed out the most impressive positive results were found in the studies were an undiluted substance was used. Edzard Ernst, a professor of complementary medicine, highlighted the problem with this:
… nobody doubts that undiluted remedies can have effects; and interestingly, the positive studies here seem to be on such medicines rather than on the highly diluted treatments which are a hallmark of homeopathy. In fact, the calendula cream found to be effective in one study is not diluted at all and thus it cannot, to all intents and purposes, be considered to be a typical homeopathic remedy.
When the evidence is as slight as it clearly is in this case Cochrane reviewers typically say so and their conclusions tend to reflect this. However, in this case the review whose lead author happened to be a ‘specialist’ in complementary cancer therapies at a Homeopathic hospital, concluded that:
This review found preliminary data in support of the efficacy of topical calendula for prophylaxis of acute dermatitis during radiotherapy and Traumeel S mouthwash in the treatment of chemotherapy-induced stomatitis. These trials need replicating. There is no convincing evidence for the efficacy of homeopathic medicines for other adverse effects of cancer treatments. Further research is required.
This to me doesn’t seem like too bad of a summary except the ‘preliminary data’ is really, really preliminary given that it is based on the results of single studies that have not been replicated. Usually Cochrane reviews dealing with such a small amount of evidence would simply state that ‘there is insufficient data from which to draw conclusions’ but not this time.
However, such issues are not what this post is about, instead this post is about the way that this review was (mis)reported in the mainstream media and specifically the headlines that were chosen to accompany the articles. Headlines are important because 1) people don’t always bother reading the information in articles and 2) people frequently remember headlines over actual content. A misleading headline can cause a lot of problems as has been documented extensively by Ben Goldacre in his column/blog ‘Bad Science‘.
The BBC’s report of the research originally had the title Homeopathy ‘eases cancer therapy’ which creates the impression that general homeopathic treatments have been shown to ‘ease cancer therapy’. This is a very misleading title since there is such a small amount of evidence and the most effective treatments in the trial are not really ‘homeopathic’ at all in that they contain significant amounts of active ingredients rather than the typical ultra dilute homeopathic remedies which frequently do not even contain one molecule of active ingredient.
The actual article however was not too bad because it actually included an extensive quote from Edzard Ernst which clearly pointed out the flaws in the research and the problems with drawing wider conclusions from the evidence considered. The BBC may even have realised that their chosen title went too far and created the wrong impression because a day later after receiving criticism on several blogs the BBC article’s title changed to ‘Homeopathy ‘no cancer care harm‘ although no indication is provided as to why (the original title can be seen from a site which sourced the article when it was published here).
This headline is slightly better but it too suffers from the problem of generating false impressions as it suggests that there was actual concern over whether homeopathic treatments could interfere with proven cancer treatments and that this has been proven not to be the case. This is also the impression given by the Newswise report whose headline reads ‘Homeopathic Meds Can Coexist With Conventional Cancer Treatment‘.
That homeopathic treatments could interfere with proven medication is not however an issue of concern, even for homeopathy’s critics. Homeopathic treatments tend to include no or super dilute amounts of active ingredients and as such typically have no chance of interfering with actual medicine. James Randi, a famous skeptic, frequently demonstrates this point at his talks by downing 64 times the prescribed dose of homeopathic sleeping pills and then proceeding to give his talk with no adverse effects.
The bottom line is that homeopathic medicines potential to interfere with other medications is about as high as the potential for interference of drinking normal water- so nobody has been calling for studies of how homeopathic treatments interact with proven treatments. What critics are actually concerned about is the potential for patients to seek homeopathic treatments instead of proven treatments!
Steven Novella, a neurologist and president of the New England Skeptical Society, also points out that such headlines are extremely misleading as they “make it seem as if there is some utility to combining homeopathic treatments with conventional cancer treatment, but even this friendly review did not show that.”
An article from Reuters also chose the same theme for it’s headline which reads ‘Homeopathy appears compatible with cancer therapy‘. Once again the article itself gives a much more accurate portrayal of the research including this telling quote from the lead author of the review, which somewhat contradicts the published positive conclusion of her review:
There are very few studies looking at homeopathic medicines for adverse effects of cancer treatments,” Kassab told Reuters Health, “and this review found no evidence of sufficient quality or quantity to support the effectiveness or ineffectiveness of these interventions.