Department of Psychosomatic Medicine and Psychotherapy, Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 8, 79104, Freiburg, Germany.
Department of Psychology, Clinical Psychology and Psychotherapy, University of Freiburg, Freiburg, Germany.
Sci Rep. 2021 Feb 16;11(1):3855. doi: 10.1038/s41598-021-83148-6.
Open-label placebos (OLPs) are placebos without deception in the sense that patients know that they are receiving a placebo. The objective of our study is to systematically review and analyze the effect of OLPs in comparison to no treatment in clinical trials. A systematic literature search was carried out in February 2020. Randomized controlled trials of any medical condition or mental disorder comparing OLPs to no treatment were included. Data extraction and risk of bias rating were independently assessed. 1246 records were screened and thirteen studies were included into the systematic review. Eleven trials were eligible for meta-analysis. These trials assessed effects of OLPs on back pain, cancer-related fatigue, attention deficit hyperactivity disorder, allergic rhinitis, major depression, irritable bowel syndrome and menopausal hot flushes. Risk of bias was moderate among all studies. We found a significant overall effect (standardized mean difference = 0.72, 95% Cl 0.39-1.05, p < 0.0001, I = 76%) of OLP. Thus, OLPs appear to be a promising treatment in different conditions but the respective research is in its infancy. More research is needed, especially with respect to different medical and mental disorders and instructions accompanying the OLP administration as well as the role of expectations and mindsets.
开放性安慰剂（OLP）是指在不欺骗患者的情况下使用安慰剂，即患者知道自己正在接受安慰剂。我们的研究目的是系统地回顾和分析与无治疗相比，OLP 在临床试验中的效果。我们于 2020 年 2 月进行了系统文献检索。纳入了比较 OLP 与无治疗的任何医疗状况或精神障碍的随机对照试验。独立评估了数据提取和偏倚风险评分。筛选了 1246 条记录，纳入了 13 项系统评价研究。其中 11 项试验符合荟萃分析的条件。这些试验评估了 OLP 对背痛、癌症相关疲劳、注意缺陷多动障碍、过敏性鼻炎、重度抑郁症、肠易激综合征和更年期热潮红的影响。所有研究的偏倚风险均为中度。我们发现 OLP 的总体效果显著（标准化均数差=0.72，95%置信区间 0.39-1.05，p<0.0001，I=76%）。因此，OLP 似乎在不同的情况下是一种有前途的治疗方法，但相应的研究还处于起步阶段。需要进行更多的研究，特别是针对不同的医学和精神障碍，以及伴随 OLP 管理的说明，以及期望和思维模式的作用。
