Authors' response: Homeopathy is safe and does not lack positive evidence in clinical trials/Scottish GPs use of Homeopathy

In response to the letters from Mathie and Fisher, and Leckridge, we would like to make the following general comments.

The purpose of our article was to report the levels of herbal and homeopathic prescribing in Scottish primary care, and not to review in detail the evidence for or against the medical use of these alternative therapies. For this reason we restricted the number of citations in our paper to the small number of well-written and robust articles on homeopathy [1].

We remain unconvinced by the apparently large evidence base presented in both letters, which rely upon selective reports from small, underpowered and difficult to interpret studies, nonrandomized ‘pragmatic’ studies, spurious inappropriate comparisons, or reviews and letters written by the correspondents themselves.

Whether deliberately or not, there also appears to have been a misunderstanding or misrepresentation of the conclusions drawn from a key review by Linde [2]. This review, cited in both letters to defend the use of homeopathy, actually concludes with the statement that ‘we found insufficient evidence from these studies that homeopathy is clearly efficacious for any single clinical condition’; a conclusion which does not support their argument for the efficacy and medical use of homeopathy.

It is also noteworthy that the ‘serious criticism’ of the ‘deeply flawed’ excellent Lancet review by Shang et al. raised in both letters relies for evidence on a letter authored by Peter Fisher [3, 4], surely not the required level of peer-reviewed evidence necessary to cast significant doubts on this meta-analysis.

As rational evidence-based physicians we agree that homeopathic preparations, which contain no active ingredient (in the traditional sense), are unlikely to give rise to any toxicity-related safety issues. We do, however, have concerns about potential safety issues which may occur when a patient is prescribed an unproven treatment, for what one must assume is a real medical condition. It is important to remember that although there is little, if any, robust safety data for complementary and alternative medicine (CAM) therapies, including homeopathy, this lack of safety data does not imply that these products are safe.

Leckridge states that there is a lack of evidence for 47% of medical treatments in use today, and correctly cites the BMJ publication Clinical Evidence as proof, the inference being that evidence is lacking for 47% of conventional medicines use, a rather disingenuous misrepresentation of the facts. Clinical Evidence covers the use of all possible medical interventions, including CAMs, such as homeopathy and herbal treatments, all of which fall into the unproven, lack of evidence group. A further important point is that not all unproven therapies are equal. Unlike homeopathy, many conventional medical interventions, such as oxygen therapy for acute asthma and diuretics for heart failure, although of unproven benefit, possess a significant scientific and medical consensus basis for their use.

On a personal level, like all rational and evidence-based practitioners we recognize and acknowledge the potential of placebo therapy for which, unlike CAM therapies, there is a comparatively good evidence base. We also have sufficient insight to recognize our desire and sometimes need to help patients. However, we do not believe that these are sufficient reasons, no matter how well meant, for the use of unproven therapies.

Finally, as required by all peer-reviewed journals, we supplied all information regarding funding sources and potential conflicts of interest to the BJCP editorial office.