Systematic Reviews on Acupuncture
Tim H. Tanaka, Ph.D.
The Pacific Wellness Institute, Toronto, Ontario, Canada
Dept. Acupuncture Moxibustion, Tsukuba University of Technology, Japan
Updated January 18, 2011
With the exception of very few recent trials that contain a large number of patients, e.g., 17-21 most of the previous acupuncture trials suffer from the drawback of a small sample size.
Thus, there are a substantial number of previous studies that are considered under-powered and the results may be contaminated by a Type II error (false negative). A systematic review attempts to systematically collect and analyze all published qualified clinical trials. All previous studies of the same topic including data from small studies are pooled together and analyzed as if they were one study (meta-analysis). Thus, the systematic review is considered to be of highest quality of evidence in EBM.
It should be kept in mind, however, that the existence of contradicting evidence is not unusual in any medical discipline. The systematic review attempts to minimize such bias by using pre-determined criteria to qualify previous studies, yet this process itself is subject to bias. It is therefore not uncommon to find contradicting conclusions from systematic reviews on the same research topic. Some researchers therefore, found it necessary to complete a “systematic review of systematic reviews”. 22-27
It is important to note that RCTs included in meta-analyses need to be conducted adequately with sufficient control and intervention protocols, otherwise, the conclusion of systematic review could be skewed. The issue of publication bias should be also mentioned. It has been indicated that certain countries tend to publish only positive studies.28 Nevertheless, the systematic review is considered the best evidence available in EBM, and healthcare practitioners and policy makers should pay close attention to these reviews.
1. Evidence-based medicine. A new approach to teaching the practice of medicine. Jama 1992;268(17):2420-5.
2. Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS. Evidence based medicine: what it is and what it isn’t. Bmj 1996;312(7023):71-2.
3. Gwei-Djen L, Needham J. Celestial Lancets: A History and Rationale of Acupunture and Moxa. London: Cambridge University Press, 1980.
4. Sackett DL. Evidence-based Medicine: How to Practice and Teach EBM. . 2nd edition ed: Churchill Livingtone, 2000.
5. Kinoshita H. Rinshoshiken karamita hosha no kentou. Nihon Shinkyu Chiryou Gakkai Shi 1971;6:6-13.
6. Gunsberger M. Acupuncture in the treatment of sore throat symptomatology. Am J Chin Med (Gard City N Y) 1973;1(2):337-40.
7. Park J, White A, Stevinson C, Ernst E, James M. Validating a new non-penetrating sham acupuncture device: two randomised controlled trials. Acupunct Med 2002;20(4):168-74.
8. Streitberger K, Kleinhenz J. Introducing a placebo needle into acupuncture research. Lancet 1998;352(9125):364-5.
9. Takakura N, Yajima H. A double-blind placebo needle for acupuncture research. BMC Complement Altern Med 2007;7:31.
10. Kleinhenz J, Streitberger K, Windeler J, Gussbacher A, Mavridis G, Martin E. Randomised clinical trial comparing the effects of acupuncture and a newly designed placebo needle in rotator cuff tendinitis. Pain 1999;83(2):235-41.
11. Tan CW, Christie L, St-Georges V, Telford N. Discrimination of real and sham acupuncture needles using the park sham device: a preliminary study. Arch Phys Med Rehabil 2009;90(12):2141-5.
12. Takakura N, Yajima H. Analgesic effect of acupuncture needle penetration: a double-blind crossover study. Open Med 2009;3(2):e54-61.
13. Guyatt GH, Heyting A, Jaeschke R, Keller J, Adachi JD, Roberts RS. N of 1 randomized trials for investigating new drugs. Control Clin Trials 1990;11(2):88-100.
14. Guyatt GH, Keller JL, Jaeschke R, Rosenbloom D, Adachi JD, Newhouse MT. The n-of-1 randomized controlled trial: clinical usefulness. Our three-year experience. Ann Intern Med 1990;112(4):293-9.
15. Jackson A, MacPherson H, Hahn S. Acupuncture for tinnitus: a series of six n = 1 controlled trials. Complement Ther Med 2006;14(1):39-46.
16. Kawakita K, Shichidou T, Inoue E, Nabeta T, Kitakoji H, Aizawa S, et al. Do Japanese style acupuncture and moxibustion reduce symptoms of the common cold? Evid Based Complement Alternat Med 2008;5(4):481-9.
17. Flachskampf FA, Gallasch J, Gefeller O, Gan J, Mao J, Pfahlberg AB, et al. Randomized trial of acupuncture to lower blood pressure. Circulation 2007;115(24):3121-9.
18. Macklin EA, Wayne PM, Kalish LA, Valaskatgis P, Thompson J, Pian-Smith MC, et al. Stop Hypertension with the Acupuncture Research Program (SHARP): results of a randomized, controlled clinical trial. Hypertension 2006;48(5):838-45.
19. Linde K, Streng A, Hoppe A, Brinkhaus B, Witt CM, Hammes M, et al. Treatment in a randomized multicenter trial of acupuncture for migraine (ART migraine). Forsch Komplementmed 2006;13(2):101-8.
20. Diener HC, Kronfeld K, Boewing G, Lungenhausen M, Maier C, Molsberger A, et al. Efficacy of acupuncture for the prophylaxis of migraine: a multicentre randomised controlled clinical trial. Lancet Neurol 2006;5(4):310-6.
21. Vickers AJ, Rees RW, Zollman CE, McCarney R, Smith CM, Ellis N, et al. Acupuncture for chronic headache in primary care: large, pragmatic, randomised trial. Bmj 2004;328(7442):744.
22. Derry CJ, Derry S, McQuay HJ, Moore RA. Systematic review of systematic reviews of acupuncture published 1996-2005. Clin Med 2006;6(4):381-6.
23. Ernst E. A systematic review of systematic reviews of homeopathy. Br J Clin Pharmacol 2002;54(6):577-82.
24. Ernst E, Canter PH. A systematic review of systematic reviews of spinal manipulation. J R Soc Med 2006;99(4):192-6.
25. Ernst E, Lee MS. Acupuncture for palliative and supportive cancer care: a systematic review of systematic reviews. J Pain Symptom Manage;40(1):e3-5.
26. Ernst E, Lee MS, Choi TY. Acupuncture for Depression? A Systematic Review of Systematic Reviews. Eval Health Prof.
27. Moore A, Jull G. The systematic review of systematic reviews has arrived! Man Ther 2006;11(2):91-2.
28. Vickers A, Goyal N, Harland R, Rees R. Do certain countries produce only positive results? A systematic review of controlled trials. Control Clin Trials 1998;19(2):159-66.