Institute of Biomedical Ethics, University of Zurich, 8008 Zurich, Switzerland.
BMC Med. 2010 Feb 23;8:15. doi: 10.1186/1741-7015-8-15.
The use of placebo interventions outside clinical trials is ethically, professionally and legally controversial. Little is known about the frequency and circumstances of placebo use in clinical practice. Our aim was to summarize the available empirical studies addressing these issues.
We searched PubMed and EMBASE from inception to July 2009 in order to identify cross-sectional surveys, qualitative or longitudinal studies among health care professionals, students or patients which investigated at least one of the following issues--frequency of placebo use or attitudes to, or motivations for, the use of placebo interventions. At least two reviewers extracted information on the study methods, participants and findings. Descriptive summaries were prepared in an iterative process by at least two reviewers per study.
Twenty-two studies from 12 different countries met the inclusion criteria. Most studies had relevant shortcomings. The proportion of respondents reporting that they had applied 'pure' placebos (for example, saline injection) during their professional life varied between 17% and 80% among physicians and between 51% and 100% among nurses, but it seems that the actual frequency of such use seems to be rare. The use of 'impure' or 'active' placebos (for example, antibiotics for viral infections) is likely to be much more frequent. However, it is impossible to make a reliable estimation because there is no agreement of what an impure placebo might be. Studies using qualitative methods or asking participants to judge case examples suggest that motivations and attitudes towards placebo use are complex and health care providers are often faced with a dilemma.
Although the available evidence is incomplete and confusing at times there can be little doubt that the prevalence of placebo use outside of clinical trials is not negligible and that views and attitudes on placebos use differ considerably among individuals, both health care professionals and patients. Further research is needed to clarify these issues.
在临床试验之外使用安慰剂干预在伦理、专业和法律方面存在争议。关于在临床实践中安慰剂的使用频率和情况知之甚少。我们的目的是总结这些问题的现有实证研究。
我们检索了 PubMed 和 EMBASE 从建立到 2009 年 7 月，以确定横断面调查、定性或纵向研究在医疗保健专业人员、学生或患者中，至少调查了以下问题之一——安慰剂使用的频率或对安慰剂干预的态度或使用的动机。至少有两名审查员提取了关于研究方法、参与者和发现的信息。至少有两名审查员对每项研究进行了描述性总结。
来自 12 个不同国家的 22 项研究符合纳入标准。大多数研究都有相关的缺陷。报告在职业生涯中使用过“纯”安慰剂（例如生理盐水注射）的医生比例在 17%到 80%之间，护士在 51%到 100%之间，但实际使用此类药物的频率似乎很少。使用“不纯”或“活性”安慰剂（例如，抗生素治疗病毒感染）的可能性要大得多。然而，由于对于不纯的安慰剂可能是什么没有达成共识，因此无法进行可靠的估计。使用定性方法或要求参与者判断案例示例的研究表明，对安慰剂使用的动机和态度是复杂的，医疗保健提供者经常面临困境。
尽管现有证据并不完整且有时令人困惑，但毫无疑问，临床试验之外安慰剂的使用频率不可忽视，并且个人、医疗保健专业人员和患者对安慰剂的使用看法和态度有很大差异。需要进一步研究来澄清这些问题。
