Placebo: Physician or Pill? RCT in a commom cold model

描述（由申请人提供）：背景。随机试验的设计和解释与“安慰剂”的使用密切相关。然而，人们对安慰剂效应的性质和程度却知之甚少。具体的目标。使用普通感冒模型，本研究将评估两种“安慰剂效应”：1)接受盲法安慰剂的效果，与不治疗相比；2)接受开放标记积极治疗（紫锥菊）的效果，与盲法积极治疗相比。本研究还将评估3)与没有就诊相比，接受标准医生就诊的效果，以及4)增强以患者为导向的就诊属性的效果。最后，我们将比较和对比这些“安慰剂效应”和“医生效应”。研究设计。一项采用平衡双向治疗结构的随机对照试验，适当时采用隐蔽分配。人口。社区招募新发普通感冒的成人。主要的结果。疾病严重天数，定义为严重持续时间曲线下的面积，严重程度以疾病特定生活质量测量的总分来衡量。二次结果。自我报告：总体健康相关生活质量、感知压力、人际支持、乐观和患者满意度。实验室测鼻洗：白细胞介素-8（炎症细胞因子），中性粒细胞计数。使用的鼻组织的计数和重量将作为鼻粘液产生的量度。权力。这项纳入800名受试者（720名预计结束者）的拟议试验将至少有80%的能力检测出治疗组之间严重程度天数的20%差异。的重要性。虽然本实验的疾病和治疗特异性结果将是有价值的，但本研究的主要重要性将是表征和比较随机分配给药丸治疗和随机分配给医生的临床相互作用的安慰剂效应。

DESCRIPTION (provided by applicant): Background. The design and interpretation of randomized trials is intimately connected to the use of "placebo." The nature and magnitude of placebo effects, however, is very poorly understood. Specific aims. Using a common cold model, this study will assess two kinds of "placebo effects": 1) the effect of receiving blinded placebo, compared to no treatment, and 2) the effect of receiving open-labeled active treatment (echinacea), compared to blinded active treatment. This study will also assess 3) the effects of receiving a standard physician visit, compared to no visit, and 4) the effects of enhancing that visit with patient-oriented attributes. Finally, we will compare and contrast these "placebo effects" and "physician effects". Research design. A randomized controlled trial using a balanced 2-way treatment structure, with concealed allocation where appropriate. Population. Community-recruited adults with new onset common cold. Primary outcome. Severity days of illness, defined as area under the severity duration curve, with severity measured as total score on an illness-specific quality of life measure. Secondary outcomes. Self-reported: general health-related quality of life, perceived stress, interpersonal support, optimism, and patient satisfaction. Laboratory-measured from nasal wash: IL-8 (inflammatory cytokine), neutrophil counts. Counts and weights of nasal tissues used will serve as measures of nasal mucus production. Power. This proposed trial of 800 enrolled participants (720 projected finishers) will have at least 80% power to detect a 20% difference in severity days between treatment groups. Importance. Although the illness- and treatment-specific results of this experiment will be valuable, the primary importance of this study will be to characterize and compare placebo effects attributable to randomization to pill treatments versus randomization to physician-based clinical-interactions.