Why Clinical Homeopathic Research Is So Difficult

By Greg Cooper, August, 2010

Scientific research has investigated homeopathy using randomized, placebo-controlled clinical trials (RCTs), which are the same types of trials that conventional medicine uses to test modern drugs. But it has been difficult for independent researchers to consistently duplicate results for RCTs in homeopathy. Some RCTs give positive results while others give no results. I will try to explain why I believe results of RCTs of homeopathy are so hard to duplicate.

Since homeopathy involves very small doses, results in homeopathy may be more sensitive to the initial conditions than results in other medical research. Getting the right remedy into the patient's mouth is one thing, but many homeopathic doctors and patients consider other conditions to also be very important.

They see homeopathy as a process, whose outcome depends not only on the patient getting the right remedy, but also on the disorder itself, the mental attitudes of the doctor and patient, their relationship, a supportive therapeutic setting and other environmental factors during treatment. Researchers doing an RCT might add that the outcome they measure depends on the size of their RCT, its quality and how the outcome is measured.

Since homeopathic remedies contain virtually no material substance, the homeopathic process might be delicate, like that of applied intentionality (4), prayer (5) or plant sensitivity (6). This could leave homeopathic effects susceptible to a negative influence from any mental stress in the lives of the patient or doctor. Clearly, this would make it very difficult to duplicate the mental states and relationships, and hence to produce the same results, in a new RCT. This is the main reason I believe results are difficult to duplicate in RCTs on homeopathy.

The problem of having similar enough initial conditions is especially serious when RCTs on homeopathy are compared to RCTs on conventional medicine. For the researchers, a large part of the challenge is to find, for each RCT on homeopathy, a match in a conventional drug RCT that is similar enough to the homeopathy RCT in size, quality, disorder studied, and outcome measure, for the comparison to be meaningful. The matching is necessary so it will be clear that any difference between the homeopathy and conventional groups is due to the different treatment and not due to one of those other factors.

Without this kind of matching, a study may base conclusions on comparisons between homeopathic and conventional RCTs that are only partially similar, for example, similar in study size and quality, while remaining different as to which disorder is involved.

This was a serious limitation of the 2005 study (3), which suggested that homeopathy is a placebo. To learn more about this and other limitations of the 2005 study, refer to the article by Rutten and Stolper (2). In this article now, I will focus on the lack of matching when homeopathy and conventional groups were compared in the widely accepted 2005 study.

Of the 8 RCTs on homeopathy and the 6 on conventional medicine selected for comparison in the 2005 study, only 2 of each (4 of 14 RCTs) are matched with an RCT of the same disorder, while all the others are unmatched - they report on different disorders. Therefore, for the most part, (10 of 14 RCTs), this study bases its findings on a comparison of homeopathy for some disorders, with conventional medicine for different disorders. Since homeopathy and conventional medicine may each work differently for different disorders, to properly compare homeopathy with conventional medicine, you must compare them with each treating the same disorder.

The results of this 2005 study, which stated that the effects of homeopathy are compatible with the placebo hypothesis and the effects of conventional treatment are not, was based on these 14 selected homeopathy and conventional RCTs that were, for the most part, treating different disorders. Their finding, therefore, could have been due to those different disorders, rather than due to the different treatment. Understanding this limitation of this study, I have become quite skeptical of its ‘placebo’ findings on homeopathy.

If you too are suspicious of the 2005 study or of the use of RCTs for homeopathy, then you'll be happy to know that there are other ways to formally study the benefits people experience from homeopathy. It fares well under large-scaled outcome studies, which are uncontrolled group studies that try to "measure health effects by global, patient-centered outcome measures" such as quality of life and severity of complaints. While it may be difficult to duplicate specific results of a RCT on homeopathy, it is easy to show through outcome studies that "homeopathic treatment as a whole may serve to help people with long standing severe chronic diseases." (1)

Results of outcome studies are more consistent than RCT results because in homeopathy, there is often an unexpected, general effect which is quite beneficial, while in RCTs, only predefined, specific effects are measured. These important, general effects arise because of the holistic nature of homeopathy, rather than because of a magic-bullet-like action for a specific effect. These valuable general effects are the other reason I believe the value of homeopathy often cannot be replicated in RCTs.

I expect that in future, more carefully prepared RCTs and meta-analyses will be done, and these will confirm the outcome studies and the holistic therapeutic effect experienced by homeopathic practitioners and patients. In the mean time, let's understand the facts and not doubt our experience.

Sources:

1) Witt C, Albrecht H (eds) New Directions in Homeopathy Research. KVC Verlag, 2009.
2) Rutten ALB and Stolper CF. The 2005 meta-analysis of homeopathy: the importance of post-publication data. Homeopathy 2008; 97: 169-177.
3) Shang A, Huwiler-Muntener K, Nartey L, et al. Are the clinical effects of homeopathy placebo effects? Comparative study of placebo-controlled trials of homeopathy and allopathy. Lancet 2005; 366: 726-732.
4) Tiller WA, Science and Human Transformation. Pavior, 1997.
5) Dossey L, Be Careful What You Pray For - You Just Might Get It. HarperCollins, 1998.
6) Tompkins P, Bird C, The Secret Life of Plants. Harper Perennial, 2002.