Janet Richardson, BSc (Hons), PhD, CPsychol, RN, DipDN, PGCE, RNT.
Research Director, School of Integrated Health, University of Westminster, and Chairman, Research Council for Complementary Medicine
The increasing public and professional interest in complementary therapies and wider access to information about them through publications and the Internet cannot be ignored, but evidence for their effectiveness is needed. So where is the best place to start when looking for evidence? A number of electronic databases exist that can provide references to articles that give some indication of the effectiveness of complementary therapies, including details of systematic reviews.
The different indexing procedures used by electronic databases and the general terms inherent in complementary therapies require different search strategies and may produce results that are not relevant to the subject area of the search. This article provides details of some of the best sources of evidence in this area, listed in Boxes 1 and 2, and suggests how an appropriate search strategy may produce the most relevant results.
Popularity of complementary therapies
It has been estimated that over 31 million visits were made to practitioners of eight established complementary therapies in 1998 in the UK (Thomas et al, 2001). The therapies were: acupuncture, chiropractic, homoeopathy, hypnotherapy, medical herbalism, osteopathy, reflexology and aromatherapy.
Six million of these visits were made for aromatherapy and four million for reflexology; 200 000 reflexology visits and 1 million acupuncture visits were provided on the NHS (Thomas et al, 2001).
In 1995, 70 per cent of oncology centres in England and Wales were providing some form of complementary therapy (White, 1998). A recent postal survey sampled 1023 women diagnosed with breast cancer and found that 22 per cent had consulted a complementary practitioner ‘in the previous 12 months’ (Rees et al, 2000). The most commonly received therapies were massage/aromatherapy, relaxation/yoga/meditation, chiropractic/osteopathy, and healing. The women in this study mainly chose complementary therapy in order to cure or slow down their cancer, and/or to relieve symptoms and side-effects of treatment.
Courses in complementary therapy delivered by, or in collaboration with, higher-education establishments are increasing in number. A recent audit carried out by one of the authors found 11 postgraduate and 32 undergraduate courses in complementary therapies were offered in the UK (Richardson, 2001). This does not include other modules and study days covering complementary therapies within nursing courses.
Nurses and midwives are responding to the public interest in complementary therapies and the availability of training in such therapies in a number of ways. Some advocate the use of therapies such as massage, reflexology and aromatherapy in hospital settings (Styles, 1997) and suggest that these therapies may benefit patients when delivered in the context of conventional nursing practice (Stevensen, 1997).
Treatments such as acupuncture are also receiving attention. Midwives, for example, are beginning to offer acupuncture to pregnant and postnatal women (West, 1997). For most nurses, however, the primary issues are about giving advice and support to patients keen to integrate complementary therapies into their health care.
The importance of evidence
Nurses have a duty to ensure that their patients are aware of the advantages and possible side-effects of particular therapies. Indeed, certain treatments, such as specific herbal remedies, may interfere with conventional pharmacological preparations, causing problems during perioperative care (Ang-Lee et al, 2001).
If nurses are to provide advice or support to patients who choose to use a complementary therapy, they need to be aware of the evidence for the effectiveness of the treatment and the potential risks. Acupuncture, for example, is an invasive procedure that, if not practised competently, may cause problems, including pneumothorax, hepatitis, and skin infections (Ernst and White, 1997; Norheim and Fonnebo, 1996; Rampes and James, 1995). Essential oils are contraindicated in a number of conditions and may be toxic unless used in appropriate quantities.
The need for an evidence base
The need for research evidence demonstrating the effectiveness of complementary therapy and the methodological issues has received some attention in nursing literature (Botting, 1997; Ersser, 1995; Richardson, 2000); however, many complementary therapies have not been adequately investigated (Hamilton and Bechtel, 1996).
So, while nurses might facilitate the use of complementary therapies, or incorporate them into their own practice, there is a corresponding need to develop a knowledge base, grounded in effectiveness and outcome assessment (Norton, 1995). This is of particular relevance in the context of an evidence-based health service.
Increasing numbers of patients are well-informed about illnesses and treatment options. A wide-range of books on complementary and alternative therapies can be found on the shelves of many high-street bookshops. Some of these offer ‘self-help’ advice on stress reduction, exercise and nutrition; others focus on particular conditions, such as insomnia, or recommend ways to ‘Boost your immune system’.
The Internet is a major source of information and there are numerous complementary and alternative therapy websites.
Information on the Internet is easily accessible, but its quality is often questionable. Anyone can put information on the world-wide web without needing to supply names, qualifications or sources, let alone whether the information is based on appropriate evidence.
In contrast, a site such as OMNI (Organising Medical Networked Information) offers free access to a searchable catalogue of Internet sites covering health and medicine, all of which have been assessed using quality assurance criteria.
The need for an evidence base for complementary therapy has been clearly articulated in the House of Lords Select Committee on Science and Technology report on Complementary and Alternative Medicine (HL Paper 123, 2000). Research that examines the effectiveness of complementary therapies requires investment in infrastructure and research capacity, as well as the application of appropriate research methodologies. The knowledge gained from this investment will need to be appropriately disseminated.
Research evidence in complementary therapy
In the quest for evidence-based practice, the strongest type of evidence is provided by systematic reviews of well-designed, randomised, controlled trials (RCTs), with strong evidence from at least one properly designed RCT of an appropriate size. The suitability of the RCT in research regarding complementary therapy has been much debated (Richardson, 2000). Furthermore, it has been argued that the RCT is an inappropriate method for researching complementary therapies, and that other approaches, such as single-case designs, qualitative approaches, outcome assessment and observational studies, are more relevant (Aldridge, 1988; St George, 1994; Melchart et al, 1997; Mercer et al, 1995).
The answer is that different methods will be appropriate for different research questions. For example, a qualitative approach is most useful for understanding a patient’s experience of a particular therapy. When making decisions about the relevance of the therapies for nursing practice, however, the best way of assessing the therapies’ effectiveness is to consider evidence from systematic reviews and RCTs.
Finding the evidence
Over two million articles are published annually in over 200 000 biomedical journals (Mulrow, 1995). A useful starting point for examining the evidence for a x therapy is to look at the reviews. There are several high-quality electronic databases and search services that specialise in, or include, material relating to complementary therapies.
Search strategy - An appropriate search strategy, using the databases identified in Boxes 1 and 2, is needed to find the most relevant review articles. These databases provide, or help you find, some of the best and most accessible sources of information on complementary therapies. However, they are not 100 per cent reliable because electronic databases cover different journals and use different indexing procedures. For example, a search for ‘massage’ on Cam on PubMed produced some results that were irrelevant to complementary therapies.
Before starting any search, it is essential first to define the ‘research question’. This will determine the search strategy and the databases that are most likely to produce relevant results. In order to get the best search results, you must first focus on what exactly it is that you want to know.
Valuable resources - There are many databases that cover specialist subjects and include complementary therapies. Medline, a database produced by the United States National Library of Medicine (NLM), is the standard database for health-care researchers. It contains 3700 journals from over 70 countries, from 1966 onwards and is updated monthly. However, focusing a search on this database alone could omit up to half of the available studies (Dickersin et al, 1995).
The Cochrane Library is a very useful resource that contains over 60 systematic reviews on complementary therapies. Some examples of published Cochrane reviews and those in progress are given in Box 2. The Cochrane clinical trials registry is a specialist source of information regarding clinical trials in complementary medicine.
The Research Council for Complementary Medicine (RCCM) has produced a comprehensive guide to searching for published information in complementary medicine (Rees 1995b, Rees 2001). The RCCM has also developed a specialist complementary therapy database (CISCOM) and search service that is available through the RCCM website. CISCOM was found by one study to be the most effective database for searching for controlled clinical trials in complementary therapy (White et al, 1995).
A source of information recently developed by the National Center for Complementary and Alternative Medicine (NCCAM) in the US and the National Library of Medicine (NLM) is CAM (Complementary and Alternative Medicine) on PubMed. This is a subset of the NLM bibliographic citations, including Medline citations, and offers computer links to more that 1700 journals. CAM on PubMed features more than 230 000 references to CAM-related articles and reports.
The NHS Centre for Reviews and Dissemination is currently preparing Effective Health Care bulletins that will synthesise the results of reviews of clinical trials in acupuncture and homoeopathy.
Implications for nursing practice
It is inevitable that nurses will come across patients who are either using complementary therapies or are keen to include them in their conventional treatment. Furthermore, the training opportunities in therapies such as massage, aromatherapy, acupuncture and reflexology may be attractive to nurses, who are keen to extend their skills and offer greater choice to patients. Nurses will, however, be required to justify their use of complementary therapies using the available evidence. This evidence will need to address issues of effectiveness and harm. While randomised controlled trials provide the most reliable form of evidence of effectiveness, nurses will also want to understand patient experience of therapies by assessing other forms of research.
Aldridge, D. (1988)Single-case research designs. Complementary Medical Research 3: 1, 37-46.
Ang-Lee, M.K., Moss, J., Yuan, C.S. (2001)Herbal medicines and perioperative care. Journal of the American Medical Association 286: 2, 208-216.
Botting, D. (1997)Review of literature on the effectiveness of reflexology. Complementary Therapies in Nursing and Midwifery 3: 5, 123-30.
Dickersin, K., Scherer, R., Lefebvre, C. (1995)Identifying relevant studies for systematic reviews. In: Chalmers, I., Altman, D.G. (eds). Systematic Reviews. London: BMJ Publishing Group.
Ernst, E., White, A. (1997)Life-threatening adverse reactions after acupuncture: A systematic review. Pain 71: 123-126.
Ersser, S.J. (1995)Complementary therapies and nursing research: issues and practicalities. Complementary Therapies in Nursing and Midwifery 1: 2, 44-50.
Hamilton, D., Bechtel, G.A. (1996)Research implications for alternative therapies. Nursing Forum 31: 1, 6-10.
House of Lords Select Committee on Science and Technology. (2000)Session 1999-2000, 6th Report (HL Paper 123), Complementary and Alternative Medicine. London: The Stationery Office.
Melchart, D., Linde, K., Weidenhammer, W. (1997)Systematic Clinical Auditing in Complementary Medicine: Rationale, concept, and a pilot study. Alternative Therapies in Health and Medicine 3: 1, 33-39.
Mercer, G., Long, A.F., Smith, I.J. (1995)Researching and Evaluating Complementary Therapies: The state of the debate. Leeds: Collaborating Centre for Health Service Research, Nuffield Institute for Health.
Mulrow, C.D. (1995)Rationale for systematic reviews. In: Chalmers I. & Altman D. (eds). Systematic Reviews. London: BMJ Publishing Group.
Norheim, A.J., Fonnebo, V. (1996)Acupuncture adverse effects are more than occasional case reports: results from questionnaires among 1135 randomly selected doctors and 197 acupuncturists. Complementary Therapies in Medicine 4: 8-13.
Norton, L. (1995)Complementary therapies in practice: the ethical issues. Journal of Clinical Nursing 4: 6, 343-8.
Rampes, H., James, R. (1995)Complications of acupuncture. Acupuncture in Medicine 13: 1, 26-33.
Rees, R.W. (1995b)CISCOM, the Centralised Information Service for Complementary Medicine. Complementary Therapies in Medicine 3: 183-186.
Rees, R.W., Feigel, I., Vickers, A. et al. (2000)Prevalence of complementary therapy use by women with breast cancer: a population-based survey. European Journal of Cancer 36: 1359-1364.
Rees, R.W. (2001)Researching complementary therapies in cancer care. In: Barraclough J. (Ed.). Integrated Cancer Care: Holistic, complementary and creative approaches. Oxford: Oxford University Press.
Richardson, J. (2000)The use of randomized control trials in complementary therapy: Exploring the methodological issues. Journal of Advanced Nursing 32: 2, 398-406.
Richardson, J. (2001)Integrated Health: a strategy for Oxford Brookes University. Unpublished project report.
Stevensen, C. (1997)Complementary therapies and their role in nursing care. Nursing Standard 11: 24, 49-53.
St George, D. (1994)Towards a Research & Development Strategy for Complementary Medicine. The Homoeopath 54: 254-257
Styles, J.L. (1997)The use of aromatherapy in hospitalised children with HIV disease. Complementary Therapies in Nursing and Midwifery 3: 1, 16-20.
Thomas, K. J., Nicholl, J.P., Coleman, P. (2001)Use and expenditure on complementary medicine in England: a population-based survey. Complementary Therapies in Medicine 9: 2-11.
West, Z. (1997)Acupuncture within the National Health Service: a personal perspective. Complementary Therapies in Nursing and Midwifery 3: 3, 83-6.
White, A., Resch, K.L., Ernst, E. (1995)Searching for acupuncture trials: Which database? Acupuncture in Medicine 13: 2, 97-99.
White, P. (1998)Complementary medicine treatment of cancer: a survey of provision. Complementary Therapies in Medicine 6: 10-13.