Pittler Max H, Brown Elizabeth M, Ernst Edzard
Complementary Medicine, Peninsula Medical School, Universities of Exeter and Plymouth, Exeter, UK.
CMAJ. 2007 Sep 25;177(7):736-42. doi: 10.1503/cmaj.061344.
Static magnets are marketed with claims of effectiveness for reducing pain, although evidence of scientific principles or biological mechanisms to support such claims is limited. We performed a systematic review and meta-analysis to assess the clinical evidence from randomized trials of static magnets for treating pain.
Systematic literature searches were conducted from inception to March 2007 for the following data sources: MEDLINE, EMBASE, AMED (Allied and Complementary Medicine Database), CINAHL, Scopus, the Cochrane Library and the UK National Research Register. All randomized clinical trials of static magnets for treating pain from any cause were considered. Trials were included only if they involved a placebo control or a weak magnet as the control, with pain as an outcome measure. The mean change in pain, as measured on a 100-mm visual analogue scale, was defined as the primary outcome and was used to assess the difference between static magnets and placebo.
Twenty-nine potentially relevant trials were identified. Nine randomized placebo-controlled trials assessing pain with a visual analogue scale were included in the main meta-analysis; analysis of these trials suggested no significant difference in pain reduction (weighted mean difference [on a 100-mm visual analogue scale] 2.1 mm, 95% confidence interval -1.8 to 5.9 mm, p = 0.29). This result was corroborated by sensitivity analyses excluding trials of acute effects and conditions other than musculoskeletal conditions. Analysis of trials that assessed pain with different scales suggested significant heterogeneity among the trials, which means that pooling these data is unreliable.
The evidence does not support the use of static magnets for pain relief, and therefore magnets cannot be recommended as an effective treatment. For osteoarthritis, the evidence is insufficient to exclude a clinically important benefit, which creates an opportunity for further investigation.
静态磁体在市场上宣称具有减轻疼痛的功效，尽管支持此类宣称的科学原理或生物学机制的证据有限。我们进行了一项系统评价和荟萃分析，以评估来自静态磁体治疗疼痛的随机试验的临床证据。
从创刊至2007年3月，对以下数据来源进行了系统的文献检索：医学文献数据库（MEDLINE）、荷兰医学文摘数据库（EMBASE）、联合与补充医学数据库（AMED）、护理学与健康领域数据库（CINAHL）、Scopus数据库、考克兰图书馆和英国国家研究注册库。纳入所有关于静态磁体治疗任何原因引起疼痛的随机临床试验。仅当试验涉及安慰剂对照或弱磁体作为对照，且以疼痛作为结局指标时才纳入。以100毫米视觉模拟量表测量的疼痛平均变化被定义为主要结局，并用于评估静态磁体与安慰剂之间的差异。
确定了29项可能相关的试验。9项使用视觉模拟量表评估疼痛的随机安慰剂对照试验纳入了主要荟萃分析；对这些试验的分析表明，在减轻疼痛方面无显著差异（加权平均差[在100毫米视觉模拟量表上]为2.1毫米，95%置信区间为-1.8至5.9毫米，p = 0.29）。排除急性效应试验和肌肉骨骼疾病以外的疾病试验的敏感性分析证实了这一结果。对使用不同量表评估疼痛的试验分析表明，各试验之间存在显著异质性，这意味着汇总这些数据并不可靠。
证据不支持使用静态磁体缓解疼痛，因此不能推荐磁体作为一种有效的治疗方法。对于骨关节炎，证据不足以排除临床上的重要益处，这为进一步研究创造了机会。
