Hospital Sant Rafael, Pg. Vall d'Hebron 107-117, 08035, Barcelona, Catalonia, Spain.
J Orthop Traumatol. 2020 Jan 28;21(1):1. doi: 10.1186/s10195-019-0540-4.
The placebo effect can account for part of the improvement seen in patients undergoing any type of treatment, be it surgical or pharmacological. The objective of this study is to quantify the placebo effect in carpal tunnel syndrome treatment.
A double-blinded randomized trial was performed with 68 patients suffering from mild to moderate carpal tunnel syndrome, divided into two groups with no statistically significant differences regarding age, weight, or degree of nerve compression. The patients were evaluated clinically and electromyographically before and after 2 months of treatment with either palmitoylethanolamide (PEA) or placebo.
The results, comparing the two groups, showed an improvement in both groups on a visual analogue scale (VAS) and Levine's questionnaire, which have been reported to show statistical differences in only a few items. In the placebo group, the mean age was 53.32 years (±13.43) and the BMI was 28.85 kg/m (±4.84). Before treatment, the average symptom severity score (SSS) on the Levine questionnaire was 2.57 (±0.74) and the functional status score (FSS) was 2.24 (±0.66). After treatment, these decreased to 2.11 (±0.81) and 1.96 (±0.77), being statistically nonsignificant for SSS (p = 0.0865) but significant for FSS (p = 0.0028). VAS showed a statistically nonsignificant decrease from 4.06 to 3.25 (p = 0.3407). After placebo treatment, SSS, FSS, and VAS improved by 0.46, 0.28, and 0.81 points or 17.89%, 12.5%, and 19.95%, respectively.
These results show an improvement in the studied parameters by up to 20%, but when compared with those published in literature, these show great variability due to the wide variety of factors involved in the placebo effect. Several factors that affect the placebo effect are discussed, and the present work tries to quantify it in carpal tunnel syndrome.
Level 2 of evidence according to "The Oxford 2011 Level of Evidence."
安慰剂效应可以解释接受任何类型治疗（手术或药物治疗）的患者病情改善的部分原因。本研究旨在量化腕管综合征治疗中的安慰剂效应。
对 68 名患有轻至中度腕管综合征的患者进行了双盲随机试验，将他们分为两组，两组在年龄、体重或神经压迫程度方面无统计学差异。在接受棕榈酰乙醇酰胺（PEA）或安慰剂治疗 2 个月后，对患者进行临床和肌电图评估。
两组结果比较显示，两组的视觉模拟量表（VAS）和 Levine 问卷均有所改善，但仅有少数项目显示出统计学差异。在安慰剂组中，平均年龄为 53.32 岁（±13.43），体重指数（BMI）为 28.85 kg/m（±4.84）。治疗前，Levine 问卷中症状严重程度评分（SSS）平均为 2.57（±0.74），功能状态评分（FSS）为 2.24（±0.66）。治疗后，这些分别降至 2.11（±0.81）和 1.96（±0.77），SSS 无统计学意义（p=0.0865），但 FSS 有统计学意义（p=0.0028）。VAS 从 4.06 降至 3.25，无统计学意义（p=0.3407）。安慰剂治疗后，SSS、FSS 和 VAS 分别改善了 0.46、0.28 和 0.81 分或 17.89%、12.5%和 19.95%。
这些结果表明，研究参数的改善高达 20%，但与文献中发表的结果相比，由于安慰剂效应涉及的因素多种多样，这些结果存在很大的变异性。讨论了影响安慰剂效应的几个因素，本研究试图对腕管综合征中的安慰剂效应进行量化。
根据“牛津 2011 年证据水平”，证据水平为 2 级。
