University Hospital Tübingen, Dept, of Psychosomatic Medicine, Tübingen, Germany.
BMC Med Res Methodol. 2011 Jun 10;11:90. doi: 10.1186/1471-2288-11-90.
Investigating the size and mechanisms of the placebo response in clinical trials have relied on experimental procedures that simulate the double-blind randomized placebo-controlled design. However, as the conventional design is thought to elucidate drug rather than placebo actions, different methodological procedures are needed for the placebo response.
We reviewed the respective literature for trials designs that may be used to elucidate the size of the placebo response and the mechanisms associated with it.
In general, this can be done by either manipulation the information provided to the subjects, or by manipulation the timing of the drug applied. Two examples of each strategy are discussed: the "balanced placebo design" (BDP) and the "balanced cross-over design" (BCD) and their variants are based on false information, while the "hidden treatment" (HT) and the ""delayed response test" (DRT) are based on manipulating the time of drug action. Since most such approaches include deception or incomplete information of the subjects they are suitable for patient only with authorized deception.
Both manipulating the information provided to subjects (BDP, DCD) or manipulating the timing of drug application (HT, DRT) allows overcoming some of the restrictions of conventional drug trials in the assessment of the placebo response, but they are feasible mostly in healthy subjects for ethical reasons.
在临床试验中，研究安慰剂反应的大小和机制依赖于模拟双盲随机安慰剂对照设计的实验程序。然而，由于传统设计被认为可以阐明药物而不是安慰剂的作用，因此需要不同的方法程序来研究安慰剂反应。
我们回顾了可能用于阐明安慰剂反应大小及其相关机制的试验设计的相关文献。
一般来说，可以通过向受试者提供的信息的操纵，或者通过操纵药物应用的时间来实现。每种策略都讨论了两个例子：基于虚假信息的“平衡安慰剂设计”（BDP）和“平衡交叉设计”（BCD）及其变体，而基于操纵药物作用时间的“隐藏治疗”（HT）和“延迟反应测试”（DRT）。由于大多数此类方法包括欺骗或不完全告知受试者，因此它们仅适用于经授权欺骗的患者。
无论是操纵向受试者提供的信息（BDP、DCD）还是操纵药物应用的时间（HT、DRT），都可以克服传统药物试验在评估安慰剂反应方面的一些限制，但由于伦理原因，这些方法主要适用于健康受试者。
