Evidence Check 2: Homeopathy - Science and Technology Committee Contents

Memorandum submitted by the Leeds Institute of Diagnostics and Therapeutics, University of Leeds (HO 15)

  1.  In addressing the questions posed in relation to the Government's use of evidence in policy-making regarding homeopathy; (1) What is the policy? (2) On what evidence is the policy based? it is important to recognise that clinical evidence is characterised by its incremental and sometimes less than perfect nature. Many clinical decisions are made on the balance of probabilities suggested by the evidence, rather than clear, unequivocal evidence to support particular decisions. Scientific evidence is supplemented by clinical experience and knowledge when clinical decisions are made in practice. Evidence used for policy-making is no different in that it too can only represent the best information available at a particular time, and equally must be balanced against other types of evidence, including economic and ethical considerations.

  1.  The proposed "evidence check" for homeopathy should therefore be undertaken within the context of our wider understanding of the nature and value of evidence in other clinical spheres.

  2.  In particular, it is important to have a clear framework for assessing the existing evidence which takes into account the gradations of certainty that are apparent in any systematic review of the literature. One such framework would be that provided by the British Medical Journal's "Best Health" project.

http://besthealth.bmj.com This Web-based project aims to inform patients and practitioners of the extent and certainty of existing scientific evidence for particular treatments and conditions. The following is extracted from this website;

  2.1.   Best Health looks at medical research that is published in journals all over the world. It does this by using Clinical Evidence, a collection of the best research evidence for doctors. Clinical Evidence gives doctors and other health care workers a good, up-to-date summary of what's known and what isn't about treating a wide range of clinical conditions. It's published by the BMJ Publishing Group.

  2.2.   Clinical Evidence looks at all the evidence and decides how well treatments work, whether the research is good enough and how serious the side effects are. Sometimes no one knows for certain whether a treatment works because the research that's been done isn't good enough. Or it could be that not enough research has been done.

  2.3.   Best Health adds to the Clinical Evidence research. It makes the evidence easy to read. It also enables patients to see the same research evidence that doctors see. Clinical Evidence gives doctors and other health care workers a good up-to-date summary of what's known and what isn't about treating a wide range of clinical conditions. It's published by the BMJ Publishing Group.

  2.4.  We follow a strict process to develop each topic on Best Health. Here are the key steps:

2.4.1.   Step 1: Selecting a topic

  2.4.2.   Best Health covers serious, long-lasting illnesses that affect many people in the UK. It also looks at more minor conditions that affect a lot of people, such as coughs and colds. We are guided by national health statistics, doctors and patient groups. The conditions we look at have been included in Clinical Evidence.

2.4.3.   Step 2: Asking the right questions

  2.4.4.  We cover the treatment options for each condition and give background information to explain the condition itself. Best Health works with the Clinical Evidence team, an international team of doctors, and patient groups to find out what matters most to doctors and patients. They might ask questions such as: What does the research say about exercise helping people with heart failure? What are the side effects of treatments for childhood asthma?

2.4.5.   Step 3: Finding the evidence

  2.4.6.  All our information is based on research evidence and high-quality medical papers. Here is how we gather this evidence:

  2.4.7.  Information about treatments—This information in Best Health is based on Clinical Evidence. To answer each question about a treatment, the Clinical Evidence medical information specialists do a thorough search for studies that measure how well treatments work. First the information specialists look for the best types of studies (called systematic reviews) and other good-quality studies called randomised controlled trials. If there are none of these studies, the information specialists look for other studies and say how much they can be relied on and what problems there are with the research.

  2.4.8.  Once the research has been collected, the information specialists weigh up the evidence and take out the studies that aren't good enough. They do this using a method developed by experts in how research is carried out.1 2 .This thorough research helps us find out which treatments work best for a condition, and also why certain treatments work. If you would like to read more about how we search for and select studies, see the Clinical Evidence website (http://clinicalevidence.bmj.com).

  2.4.9.  Information about conditions—The information that we provide to explain medical conditions is based on high-quality original medical papers and textbooks chosen by our information specialists. On each page of the site, you will find the details of the sources of information we have used.

2.4.10.   Step 4: Making sense of the evidence

  2.4.11.  The research evidence for each treatment is studied and summarised by a doctor who is an important expert in a particular specialty. Each topic is then checked by at least three more doctors. Then, a leading expert provides advice on how doctors can use this research evidence. We ask people with the condition to tell us what they think the important questions are about their condition and treatments.

  2.4.12.  A team of experienced medical writers makes sure this evidence can easily be understood by the general public and writes the extra information that explains each condition.

  2.4.13.  Deciding which treatments work—We group treatments into categories according to how good the evidence is that they work. We use slightly different language to describe the categories than you'll find in Clinical Evidence, but the treatments are grouped in the same way. Here is an explanation of what each category means:

CategoryWhat it means
Treatments that workThere's clear evidence from randomised controlled trials that the treatment works. Also, the evidence shows that the chance of problems is small compared with the benefits.
Treatments that are likely to workThere is some evidence that the treatment works. But we can't be as certain that the treatment works as we can for those listed under "Treatments that work".
Treatments that work, but whose harms may outweigh benefits There's some good evidence that the treatment works. But there's also good evidence that it can have serious side effects. Doctors and patients need to weigh up the benefits and risks according to what each person needs and wants.
Treatments that need further studyWe don't know if the treatment is effective because there is either too little research to tell or the quality of the research is not good enough.
Treatments that are unlikely to workThere is evidence that the treatments probably don't work. But we can't be as certain that the treatments don't work as we can for the ones in the group "Treatments that are likely to be ineffective or harmful".
Treatments that are likely to be ineffective or harmful Clear evidence shows the treatments don't work or will be harmful.

2.5.   Step 5: Presenting the answers

  All the information on Best Health is edited by a team of editors and checked by our doctors. The information about drugs has been reviewed by a team of qualified pharmacists working in association with PharmacyHealthLink. PharmacyHealthLink is a leading national charity that works to improve the health of the public through the expertise of pharmacists and their staff.

2.6.   Sources for the information on this page:

  Sackett DL, et al. Clinical epidemiology: a basic science for clinical medicine. Little, Brown and Co, Boston, USA; 1991.

  Jadad A. Randomised controlled trials. In: Assessing the quality of RCTs: why, what, how and by whom? London, UK; 1998.

  3.  Using this framework, the BMJ group have assessed 2,500 commonly used treatments and their summarised findings are shown in the figure below.

  4.  Again, it seems appropriate that the committee's deliberations regarding the evidence relating to homeopathy are conducted with reference to the larger picture regarding the imperfect and emerging evidence base informing policy for commonly provided treatments within the NHS.

  5.  While evidence-based policy is a laudable goal, something to be strived for, it can only happen in the prevailing climate of imperfect and emerging knowledge. If, as seems likely, an unacceptable gap is identified between the level of reported use of homeopathy and the evidence available to help inform the public or the NHS of its value, the most objective and ethical way forward would be to support the generation of high quality research findings to close this gap. The current structures of the NIHR are adequate to facilitate this.

  6.  The above recommendations for further research echo those made in relation to homeopathy in the GO-Science Review of the Department of Health:

    "[…]. Flagship trials should be run in the most promising areas, chosen on plausibility, and patient demand. […] The Health Technology Assessment Programme provided a framework that should be as applicable to research on homeopathy as to any other therapy."

GO-Science Review of the Department of Health, Annex 1 (2008). Government Office for Science: Department for Innovation, Universities and Skills; Paragraph 3.16.


The author of this submission, Professor Katharine Thomas, is an academic researcher at the University of Leeds; she is not a homeopathic practitioner, and has no financial interest in the provision of homeopathy.

Katharine Thomas BA (Hons) MA

Professor of Complementary and Alternative Medicine Research

Leeds Institute of Diagnostics and Therapeutics

University of Leeds

November 2009

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