The debate about the value of homeopathy — a therapeutic method that often uses highly diluted preparations of substances whose effects when administered to healthy subjects correspond to the manifestation of the disorder in the unwell patient1 — is as old as homeopathy itself. In recent decades, about 150 controlled clinical trials of homeopathy have been published. The results were neither all negative nor all positive. In such situations, some commentators resort to “cherry picking” — choosing those findings that fit their own preconceptions. The problem of selective citation is most effectively overcome by evaluating all reliable evidence, an aim best met by systematic reviews.
Even at the level of systematic reviews, the evidence on homeopathy is not entirely uniform. For instance, a Lancet review of 1997 concluded that “the clinical effects of homeopathy are not completely due to placebo”,2 while another systematic review, published in the same journal in 2005, concluded that “the clinical effects of homeopathy are placebo effects”.3 In 2002, I conducted a systematic review of 17 systematic reviews and concluded that “the best clinical evidence for homeopathy available to date does not warrant positive recommendations of its use in clinical practice”.4
Homeopaths have argued that systematic reviews that fail to generate positive conclusions about homeopathy are biased.5 It is therefore necessary to seek out those systematic reviews of research into homeopathy that are least likely to be biased. Several authors have demonstrated that Cochrane reviews tend to be superior to other reviews; they are more rigorous, more transparent, less biased and more up to date.6 In a word, they might be considered the “best”. Therefore, the aim of this article is to summarise and appraise the findings from Cochrane reviews of studies of homeopathy.
~ more... ~
Wednesday, April 21, 2010
Homeopathy: what does the "best" evidence tell us?
Subscribe to:
Post Comments (Atom)
image from http://www.spitting-image.net
1 comment:
You write, "For instance, a Lancet review of 1997 concluded that “the clinical effects of homeopathy are not completely due to placebo”.
And the next sentence in that conclusion said, "However, we found insufficient evidence from these studies that homeopathy is clearly efficacious for any single clinical condition."
My point being that it isn't just trials that get cherry-picked. Homeopaths love to quote that one sentence from the Linde 1997 paper and ignore the rest.
They also forget to mention Linde’s 1999 follow-up paper, which said:
"The evidence of bias [in homeopathic trials] weakens the findings of our original meta-analysis. Since we completed our literature search in 1995, a considerable number of new homeopathy trials have been published. The fact that a number of the new high-quality trials… have negative results, and a recent update of our review for the most “original” subtype of homeopathy (classical or individualized homeopathy), seem to confirm the finding that more rigorous trials have less-promising results. It seems, therefore, likely that our meta-analysis at least overestimated the effects of homeopathic treatments."
And they ignore the brief article by Klaus Linde and Wayne Jonas published in the Lancet 8 years later and saying this:
" We agree (with Shang et al) that homoeopathy is highly implausible and that the evidence from placebo-controlled trials is not robust."
And this:
"Our 1997 meta-analysis has unfortunately been misused by homoeopaths as evidence that their therapy is proven."
Just saying.
Post a Comment