How large are the nonspecific effects of acupuncture? A meta-analysis of randomized controlled trials

BMC Medicine

Research Article

Antonius Schneider¹  Klaus Linde¹  Karin Niemann¹  Karin Meissner² 

[1] Institute of General Practice, Technische Universität München, Orleansstrasse 47, D-81667, Munich, Germany;Institute of General Practice, Technische Universität München, Orleansstrasse 47, D-81667, Munich, Germany;Institute of Medical Psychology, Ludwig-Maximilians-University, Goethestrasse 31, D-80336, Munich, Germany;

关键词: Sham Group;    Standardize Mean Difference;    Acupuncture Intervention;    Nonspecific Effect;    Skin Penetration;   

DOI  :  10.1186/1741-7015-8-75

 received in 2010-07-17, accepted in 2010-11-23,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundWhile several recent large randomized trials found clinically relevant effects of acupuncture over no treatment or routine care, blinded trials comparing acupuncture to sham interventions often reported only minor or no differences. This raises the question whether (sham) acupuncture is associated with particularly potent nonspecific effects. We aimed to investigate the size of nonspecific effects associated with acupuncture interventions.MethodsMEDLINE, Embase, Cochrane Central Register of Controlled Clinical Trials and reference lists were searched up to April 2010 to identify randomized trials of acupuncture for any condition, including both sham and no acupuncture control groups. Data were extracted by one reviewer and verified by a second. Pooled standardized mean differences were calculated using a random effects model with the inverse variance method.ResultsThirty-seven trials with a total of 5754 patients met the inclusion criteria. The included studies varied strongly regarding patients, interventions, outcome measures, methodological quality and effect sizes reported. Among the 32 trials reporting a continuous outcome measure, the random effects standardized mean difference between sham acupuncture and no acupuncture groups was -0.45 (95% confidence interval, -0.57, -0.34; I2 = 54%; Egger's test for funnel plot asymmetry, P = 0.25). Trials with larger effects of sham over no acupuncture reported smaller effects of acupuncture over sham intervention than trials with smaller nonspecific effects (β = -0.39, P = 0.029).ConclusionsSham acupuncture interventions are often associated with moderately large nonspecific effects which could make it difficult to detect small additional specific effects. Compared to inert placebo interventions, effects associated with sham acupuncture might be larger, which would have considerable implications for the design and interpretation of clinical trials.

【 授权许可】

CC BY   
© Linde et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.