Conclusions 

There are a considerable number of systematic reviews on the effectiveness of complementary therapies available. The compilation presented is preliminary and has to be interpreted with caution. Many of the reviews describe interesting results but firm conclusions can be drawn rarely as the amount and quality of research are in general limited. Much of the research reviewed is a reflection of poor research funding and the lack of an adequate infrastructure which is competent and experienced both in methodology and complementary therapies. Without the development of a research infrastructure which reflects the actual prevalence and relevance of complementary therapies in health care, an adequate evaluation of this huge field is not possible.

Apart from few exceptions like stimulation of the acupuncture point P6 for nausea, hypericum for mild or moderately severe depressive disorders, or spinal manipulation for acute low back pain the available evidence from clinical trials is insufficient to recommend complementary interventions to health care professionals who did not use these techniques before. However, many complementary interventions are already widely used by a large number of physicians and other providers who claim positive experiences. A large number of patients seeks complementary care and perceive such treatment as effective. At least the most relevant topics should be investigated systematically.

Criteria for setting preferences to select research questions are 1) the prevalence of an intervention; 2) the relevance of the condition and the degree of satisfaction with actually available standard treatments; 3) possible risks associated with the intervention.

The choice of the adequate research methodology should not be fixed a priori but reflect a compromise between: a) relevance, b) scientific rigour and c) feasibility. Furthermore, the research approach should not focus on one single audience but ensure maximum medicine acceptability for patients; the scientific community; providers; and decision makers. Sound evaluation of clinical effectiveness will require significant resources. However, if such trials evaluating unconventional therapies arenot undertaken the discussion concerning the safety and effectiveness of unconventional medicine will remain dominated mainly by prejudices, inadequate generalisations and uncertainty.

There is a relevant number of reviews of clinical trials of various other interventions including transcendental meditation [66], biofeedback [67-70], relaxation [70-71], food supplements [72-76], balneotherapy and climatetherapy [77] or transcutaneous electrical nerve stimulation (TENS) [78]. The majority of these reviews claim at least positive trends and a need for further research.

REFERENCES

  1. Vickers AJ. Can acupuncture have specific effects on health? A systematic review of acupuncture antiemesis trials.J Roy Soc Med 1996; 89:303-311.
  2. Patel MS, Gutzwiller F, Paccaud et al A meta-analysis of acupuncture for chronic pain. Int J Epidemiol 1989; 18:900-906.
  3. ter Riet G, Kleijnen J, Knipschild P. Acupuntuur en chronische pijn. Huisarts en wetenschap 1989; 32,6:230-238.
  4. ter Riet G, Kleijnen J, Knipschild P. Acupuncture and chronic pain: a criteria-based meta-analysis. J Clin Epidemiol 1990; 43,11:1191-1199.
  5. ter Riet G, Kleijnen J, Knipschild P. Acupunctuur bij migraine en spanningshoofdpijn. Huisarts en wetenschap 1989; 32,7:258-263.
  6. ter Riet G, Kleijnen J, Knipschild P. Acupunctuur en aangezichtspijn. Huisarts en wetenschap 1989;32,7:264-266.
  7. ter Riet G, Kleijnen J, Knipschild P. Acupunctur en nekpijn/rugpijn. Huisarts en wetenschap 1989; 32,6:223-227.
  8. ter Riet G, Kleijnen J, Knipschild P. Acupunctuur en rEuropean Unionmatoide artritis. Huisarts en wetenschap 1989; 32,6:228-229.
  9. Volmink J, Lancaster T, Gray S, Silagy C. Treatments for postherpetic nEuropean Unionralgia - a systematic review of randomized controlled trials. Family Practice 1996; 13:84-91.
  10. Gabriel SE, Bombardier C. Clinical trials in fibrositis: a critical review and future directions. J RhEuropean Unionmatol 1989; 116:177-179.
  11. Jacobs JWG, Rasker JJ, vanRiel PLCM, Griebnau FWJ, vandePutte LBA. Alternatieve behandelingswijzen bij rEuropean Unionmatische aandoeningen; een literatuuronderzoek. Ned Tijdschr Geneeskd 1991; 135:317-322.
  12. Puett DW, Griffin MR. Published trials of nonmedical and noninvasive therapies for hip and knee osteoarthritis. American College of Physicians 1994; 121:133-140.
  13. ter Riet G, Kleijnen J, Knipschild P. Acupunctuur en astma. Huisarts en wetenschap 1989; 32,7:267-272.
  14. Kleijnen J, ter Riet G, Knipschild P. Acupuncture and asthma: a review of controlled trials. Thorax 1991;46:799-802.
  15. Linde K, Worku F, Stör W, et al. Randomized clinical trials of acupuncture for asthma - a systematic review. Forsch Komplement.rmed 1996; 3:148-155.
  16. Linde K, Jobst K, Panton J. Acupuncture for the treatment of asthma bronchiale. In: Cates C, Ducharme F, Gibson P, Jones P, Rowe B, Wolf F, editors. Airways of The Cochrane Database of Systematic Reviews. 2nd ed. Oxford: The Cochrane Collaboration, 1997:1-14
  17. ter Riet G, Kleijnen J, Knipschild P. A meta-analysis of studies into the effect of acupuncture in addiction. Br J Gen Prac 1990; 40:379-382
  18. White AR, Resch KL, Ernst E. Smoking cessation with acupuncture? A ' Best evidence synthesis '. Forschende Komplementärmedizin 1997; 4:102-105.
  19. White AR, Rampes H. Acupuncture in smoking cessation. In: Lancaster T, Silagy C (eds.). Tobaccos addiction module of The Cochrane Database of Systematic Reviews. Available in The Cochrane Library. The Cochrane Collaboration. Oxford: Update Software; 1997. 
  20. Law M, Tang JL. An analysis of the effectiveness of interventions intended to help people stop smoking. Arch Intern Med 1995; 155:1933-1941.
  21. Ernst E, White AR. Acupuncture as an adjuvant therapy in stroke rehabilitation? Wien Med Wschr 1996;146:556-558.
  22. Rampes H, James R. Complications of acupuncture. Acupunct Med 1995;:26-33
  23. Ernst E, White A. Life-threatening adverse reactions after acupuncture? A systematic review. Pain 1997; 71:123-126.
  24. Norheim AJ, Fonnebo V. Acupuncture adverse effects are more than occasional case reports: results from questionnaires among 1135 randomly selected doctors, and 197 acupuncturists. Compl Ther Med 1996;4:8-13.
  25. Boissel JP, Cucherat M, Haugh M, Gauthier E. Critical literature review on the effectiveness of homoeopathy: overview of data from homoeopathic medicine trials. In: Homeopatic Medicine Research Group. Report to the Commission Of The European Union Communities, 1996:195-210.
  26. Linde K, Clausius N, Ramirez G, et al. Are all effects of homeopathy placebo effects. A meta-analysis of randomized placebo-controlled trials. Lancet 1997;350 (accepted for publication)
  27. Hill C, Doyon F. Review of randomized trials of homoeopathy. Rev Epidém et Santé Publ 1990;38:139-147.
  28. Kleijnen J, Knipschild P, ter Riet G. Clinical trials of homoeopathy. Br.Med.J. 1991; 302:316-323.
  29. Lutz C. Quantitative Meta-Analyse empirischer Ergebnisse der Homopathie-forschung.Universitat Freiburg: Diplomarbeit Psychologisches Institut, 1993.
  30. Wiesenauer M, Lüdtke R. A meta-analysis of the homeopathic treatment of pollinosis with Galphimia glauca. Forsch Komplementärmed 1996;3:230-236.
  31. Reilly D, Taylor MA, Beattie NGM, et al. Is evidence for homoeopathy reproducible?Lancet 1994;344:1601-1606.
  32. Kerr HD, Saryan LA. Arsenic content of homeopathic medicines. Clin Toxicol 1986;24:451-459.
  33. Carlsson T, Bergqvist L, Hellgren U. Homeopatiska medel ger falsk säkerhet. Läkartidningen 1995;92:4467-4468
  34. Ernst E. St. John's Wort, an anti-depressant? A systematic, criteria-based review. Phytomedicine 1995; 2:(1)67-71.
  35. Linde K, Ramirez G, Mulrow CD, Pauls A, Weidenhammer W, Melchart D. St John's wort for depression - an overview and meta-analysis of randomised clinical trials. Br Med J 1996;313:253-258.
  36. Woelk H, Burkhard G, Grünwald J. Benefits and risks of the Hypericunconventional medicine extract LI160: drug monitoring study with 3250 patients. J Geriatr Psychiatr Neunrol 1994;7(suppl):34-38.
  37. Weib G, Kallischnigg G. Gingko-biloba-Extrakt (EGb 761) - Meta-Analyse von Studien zunconventional medicine Nachweis der therapEuropean Uniontischen Wirksamkeit bei Hirnleistungsstörungen bzw. peripherer arterieller Verschlubkrankheit. Muench med Wschr 1991; 10:138-142.
  38. Kleijnen J, Knipschild P. Gingko biloba for cerebral insufficiency. Br J clin Pharm 1992; 34:352-358.
  39. Hopfenmüller W. Nachweis der therapEuropean Uniontischen Wirksamkeit eines Ginkgo biloba-Spezialextraktes -Meta-Analyse von 11 klinischen Studien mit Patienten mit Hirnleistungsstörungen im Alter. Arzneim -Forsch /Drug Res 1994; 44(II):1005-1013.
  40. Letzel H, Schoop W. Gingko-biloba-Extrakt EGb 761 und Pentoxifyllin bei Claudicatio intermittens. Sekundäranalyse zur klinischen Wirksamkeit. VASA 1992; 21:403-410.
  41. Schneider B. [Ginkgo biloba extract in peripheral arterial diseases. Meta-analysis of controlled clinical studies]. Arzneimittelforschung 1992; 42:428-436.
  42. Kleijnen J, Knipschild P, ter Riet G. Garlci, onions and cardiovascular risk factors. A review of the evidence from human experiments with emphasis on commercially available preparations. Br J clin Pharm 1989; 28:535-544.
  43. Warshafsky S, Kamer RS, Sivak SL. Effect of garlic on total serunconventional medicine cholesterol. Ann Int Med 1993; 119:599-605.
  44. Silagy C, Neil A. Garlic as a lipid lowering agent - a meta-analysis. J Roy Col Phys 1994; 28:39-45.
  45. Neil HAW, Silay CA, Lancaster T, et al. Garlic powder in the treatment of moderate hyperlipidaemia: a controlled trial and meta-analysis. J Roy Coll Phys 1996;30:329334.
  46. Kleijnen J. Controlled clinical trials in humans on the effects of garlic supplements. In: Kleijnen J, editor. Food supplements and their efficacy. Maastricht: Rijksuniversiteit Limburg, 1991:73-82.
  47. Morse PF, Horrobin DF, Manku MS, Stewart JCM, Allen R, Littlewood S, et al. Meta-analysis of placebo-controlled studies of the efficacy of Epogam in the treatment of atopic eczema. Relationship between plasma essential fatty acid changes and resonenses. Br J Derml 1989; 121:75-90
  48. Kleijnen J, ter Riet G, Knipschild P. Evening primrose oil. In: Kleijnen J, editor. Food supplements and their efficacy. Maastricht: Rijksuniveriteit Limburg, 1991:51-61
  49. Budeiri D, Li Wan Po A, Dornan JC. Is Evening Primrose Oil of value in the treatment of premenstrual syndrome ? Cont Clin Trials 1996; 17:60-68.
  50. Kiene H. Klinische Studien zur Misteltherapie der Krebserkrankung. Eine kritische Würdigung. Herdecke: Dissertation, 1989. (see also Kiene H. Klinische Studien zur Misteltherapie karzinomatöser Erkrankungen. Therapeutikon 1989; 6:347-353.)
  51. Kleijnen J, Knipschild P. Mistletoe treatment for cancer Review of controlled trials in humans. Phytomedicine 1994; 1:255-260.
  52. Melchart D, Linde K, Worku F, Bauer R, Wagner H. Immunomodulation with Echinacea - a systematic review of controlled clinical trials. Phytomedicine 1994; 1:245-254.
  53. Diehm C. The role of oedema protective drugs in the treatment of chronic venous insufficiency: a review of evidence based on placebo-controlled clinical trials with regard to efficacy and tolerance. Phlebology 1996;11:23-29.
  54. Ernst E, de Smet PAGM. Risks associated with complementary therapies. In: DGBes MNG (ed). Meyer's side effects of drugs. 13th edition. Amsterdam: Elsevier 1996 1427-1454
  55. de Smet PAGM Health risks of herbal remedies. Drug safety 1995; 13: 81-91
  56. Assendelft WJJ Koes BW, van der Heijden GJMG, Bouter LM The efficacy of chiropractic manipulation for back pain: blinded review of relvant randomized clinical trials. Man Phys Ther 1992; 15:487-493
  57. Assendelft WJJ Bouter LM Does the goose really lay golden eggs? A methodological review of workmen's compenon studies J Manip Physiol Ther 1993; 16:161-168
  58. Assendelft WJJ Koes BW, van der Heijden GJMG, Bouter LM. The effectiveness of chiropractic for treatment of low back pain: an update and attempt at statistical pooling. J Man Phys Ther 1996; 19:499-507.
  59. Abenheim L, Bergeron AB. Twenty years of randomized clinical trials of manipulative therapy for back pain: a review. Clin Invest Med 1992; 15:527-535.
  60. Anderson R, Meeker WC, Wirick BE, Mootz RD, Kirk DH, Adams A. A meta-analysis of clinical trials of spinal manipulation. J Man Phys Ther 1992; 15,3:181-194.
  61. Shekelle PG, Adams AH, Chassin MR, Hurwitz EL, Brook RH. Spinal manipulation for low-back pain. Ann Int Med 1992; 117:590-598.
  62. Ottenbacher K, di Fabio R. Efficacy of spinal manipulation/mobilization therapy - a meta-analysis. Spine 1985; 10,9:81-85.
  63. Koes BW, Assendelft WJJ, van der Hejden GJMG, Bouter LM, Knipschild P. Spinal manipulation and mobilisation for back and neck pain: a blinded review. Br.Med.J. 1991; 303:1298-1303.
  64. Aker PD, Gross AR, Goldsmith CH, Peloso P. Conservative management of mechanical neck pain: systematic overview and meta-analysis. BMJ 1996; 313:1291-1296.
  65. Assendelft WJJ, Bouter LM, Knipschild PG. Complications of spinal manipulation. J Fam Pract1996;42:475-480.
  66. Alexander CN, Rainforth MV, Gelderloos P. Transcendental meditation, self actualization, and psychological health: a conceptual overview and statistical meta-analysis. J Soc Behav Pl 1991; 6:189-247.
  67. Glanz M, Klawansky S, Stason W, Berkey C, Shah N, Phan H, et al. Biofeedback Therapy in Poststroke Rehabilitation: A Meta-Analysis of the RCTs. Arch Phys Med Rehabil 1995; 76:508-515.
  68. Moreland J, Thomson MA. Efficacy of electromyographic biofeedback compared with conventional physical therapy for upper-extremity function in patients following stroke: a research overview and meta-analysis. Phys Ther 1994; 74:534-543.
  69. Schleenbaker RE, Mainous AG. Electromyographic biofeedback for nEuropean Unionro-muscular reeducation in the hemiplegic stroke patient: a meta-analysis. Arch Phys Med Rehabil 1993; 74:1301-1304.
  70. Eppley KR, Abrams AI, Shear J. Differential effects of relaxation techniques on trait anxiety: a meta-analysis. J Clin Ps 1989; 45:957-974.
  71. Eisenberg DM, Delbanco TL, Berkey CS, et al. Cognitive behavioral techniques for hypertension: are they effective. Ann Int Med 1993; 118:964-972.
  72. Appel LJ, Miller III ER, Seidler AJ, Whelton PK. Does Supplementation of Diet With 'Fish Oil' Reduce Blood Pressure? Arch Intern Med 1993; 153:1429-1438.
  73. Bielory L, Gandhi R. Asthma and vitamin C. Annals of Allergy 1994; 73:89-100.
  74. Gapinski JP, VanRuiswyk JV, et al Preventing restenosis with fish oils. Arch Intern Med 1993; 153:1595-1601.
  75. Kleijnen J, Knipschild P. Niacin and Vitamin B6 in mental functioning: a review of controlled trials in humans. Biol psych 1991; 29:931-941.
  76. Morris management committee, Sacks F, Rosner B. Does Fish Oil Lower Blood Pressure? Circulation1993; 88:523-533.
  77. Wagemans F. Effectiviteit van Kuuroord-behandelingen. Maastricht: Rijksuniversiteit Limburg, 1990.
  78. Reeve J, Menon D, Corabian P. Transcutaneous Electrical Nerve Stimulation (TENS ): a technology assessment. Int J Techn Ass 1996; 12:299-324.

Research Council for Complementary Medicine, The Royal London Homoeopathic Hospital,
UCLH NHS Foundation Trust, 60 Great Ormond Street, London, WC1 3HR
Email: info@rccm.org.uk Website: www.rccm.org.uk