Highly diluted homeopathic remedies are pure placebos! This is what the best evidence clearly shows. Ergo they cannot be shown in a rigorous study to have effects that differ from placebo. But now there is a study that seems to contradict this widely accepted conclusion.
Can someone please help me to understand what is going on?
In this double-blind, placebo-controlled RCT, 60 patients suffering from insomnia were treated either individualised homeopathy (IH) or placebo for 3 months. Patient-administered sleep diary and Insomnia Severity Index (ISI) were used the primary and secondary outcomes respectively, measured at baseline, and after 3 months.
Five patients dropped out (verum:2,control:3).Intention to treat sample (n=60) was analysed. Trial arms were comparable at baseline. In the verum group, except sleep diary item 3 (P= 0.371), rest of the outcomes improved significantly (all P < 0.01). In the control group, there were significant improvements in diary item 6 and ISI score (P < 0.01) and just significant improvement in item 5 (P= 0.018). Group differences were significant for items 4, 5 and 6(P < 0.01) and just significant (P= 0.014) for ISI score with moderate to large effect sizes; but non-significant (P > 0.01) for rest of the outcomes.
The authors concluded that in this double-blind, randomized, prospective, placebo-controlled, two parallel arms clinical trial conducted on 60 patients suffering from insomnia, there was statistically significant difference measured in sleep efficiency, total sleep time, time in bed, and ISI score in favour of homeopathy over placebo with moderate to large effect sizes. Group differences were non-significant for rest of the outcomes(i.e. latency to fall asleep, minutes awake in middle of night and minutes awake too early). Individualized homeopathy seemed to produce significantly better effect than placebo. Independent replications and adequately powered trials with enhanced methodological rigor are warranted.
I have studied this article in some detail; its methodology is nicely and fully described in the original paper. To my amazement, I cannot find a flaw that is worth mentioning. Sure, the sample was small, the treatment time short, the outcome measure subjective, the paper comes from a dubious journal, the authors have a clear conflict of interest, even though they deny it – but none of these limitations has the potential to conclusively explain the positive result.
In view of what I stated above and considering what the clinical evidence so far tells us, this is most puzzling.
A 2010 systematic review authored by proponents of homeopathy included 4 RCTs comparing homeopathic medicines to placebo. All involved small patient numbers and were of low methodological quality. None demonstrated a statistically significant difference in outcomes between groups.
My own 2011 not Medline-listed review (Focus on Alternative and Complementary Therapies Volume 16(3) September 2011 195–199) included several additional studies. Here is its abstract:
The aim of this review was the critical evaluation of evidence for the effectiveness of homeopathy for insomnia and sleep-related disorders. A search of MEDLINE, AMED, CINAHL, EMBASE and Cochrane Central Register was conducted to find RCTs using any form of homeopathy for the treatment of insomnia or sleep-related disorders. Data were extracted according to pre-defined criteria; risk of bias was assessed using Cochrane criteria. Six randomised, placebo-controlled trials met the inclusion criteria. Two studies used individualised homeopathy, and four used standardised homeopathic treatment. All studies had significant flaws; small sample size was the most prevalent limitation. The results of one study suggested that homeopathic remedies were superior to placebo; however, five trials found no significant differences between homeopathy and placebo for any of the main outcomes. Evidence from RCTs does not show homeopathy to be an effective treatment for insomnia and sleep-related disorders.
It follows that the new trial contradicts previously published evidence. In addition, it clearly lacks plausibility, as the remedies used were highly diluted and therefore should be pure placebos. So, what could be the explanation of the new, positive result?
As far as I can see, there are the following possibilities:
- some undetected/undisclosed bias,
- homeopathy works after all.
I would be most grateful, if someone could help solving this puzzle for me (if needed, I can send you the full text of the new article for assessment).