Bauml Joshua, Xie Sharon X, Farrar John T, Bowman Marjorie A, Li Susan Q, Bruner Deborah, DeMichele Angela, Mao Jun J
Division of Hematology/Oncology (JB, AD), Center for Clinical Epidemiology and Biostatistics (SXX, JTF, AD, JJM), Department of Anesthesia and Critical Care (JTF), Department of Family Medicine and Community Health (SQL, JJM), Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (JB, AD); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (JB, AD, JJM); Center for Clinical Epidemiology and Biostatistics (SXX, JTF, AD, JJM) and Department of Anesthesia and Critical Care (JTF), Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA; Boonshoft School of Medicine, Wright State University, Dayton, OH (MAB); Nell Hodgson School of Nursing, Emory University, Atlanta, GA (DB).
J Natl Cancer Inst Monogr. 2014 Nov;2014(50):302-7. doi: 10.1093/jncimonographs/lgu029.
The large placebo effect observed in prior acupuncture trials presents a substantial challenge for interpretation of the efficacy of acupuncture. We sought to evaluate the relationship between response expectancy, a key component of the placebo effect over time, and treatment outcome in real and sham electroacupuncture (EA).
We analyzed data from a randomized controlled trial of EA and sham acupuncture (SA) for joint pain attributable to aromatase inhibitors among women with breast cancer. Responders were identified using the Patient Global Impression of Change instrument at Week 8 (end of intervention). The Acupuncture Expectancy Scale (AES) was used to measure expectancy four times during the trial. Linear mixed-effects models were used to evaluate the association between expectancy and treatment response.
In the wait list control group, AES remained unchanged over treatment. In the SA group, Baseline AES was significantly higher in responders than nonresponders (15.5 vs 12.1, P = .005) and AES did not change over time. In the EA group, Baseline AES scores did not differ between responders and nonresponders (14.8 vs 15.3, P = .64); however, AES increased in responders compared with nonresponders over time (P = .004 for responder and time interaction term) with significant difference at the end of trial for responders versus nonresponders (16.2 vs 11.7, P = .004).
Baseline higher response expectancy predicts treatment response in SA, but not in EA. Divergent mechanisms may exist for how SA and EA influence pain outcomes, and patients with low expectancy may do better with EA than SA.
先前针灸试验中观察到的较大安慰剂效应给解释针灸疗效带来了重大挑战。我们试图评估预期反应（安慰剂效应随时间变化的关键组成部分）与真实电针和假电针治疗结果之间的关系。
我们分析了一项针对乳腺癌女性因芳香化酶抑制剂引起的关节疼痛进行电针和假针灸随机对照试验的数据。在第8周（干预结束时）使用患者整体印象变化量表确定反应者。在试验期间使用针灸预期量表（AES）四次测量预期。使用线性混合效应模型评估预期与治疗反应之间的关联。
在等待列表对照组中，AES在治疗期间保持不变。在假针灸组中，反应者的基线AES显著高于无反应者（15.5对12.1，P = 0.005），且AES随时间没有变化。在电针组中，反应者和无反应者的基线AES评分没有差异（14.8对15.3，P = 0.64）；然而，随着时间的推移，反应者的AES相对于无反应者有所增加（反应者与时间交互项的P = 0.004），试验结束时反应者与无反应者之间存在显著差异（16.2对11.7，P = 0.004）。
基线较高的反应预期可预测假针灸的治疗反应，但不能预测电针的治疗反应。假针灸和电针影响疼痛结果的机制可能不同，预期较低的患者接受电针治疗可能比假针灸更好。
