Bishop Felicity L, Greville-Harris Maddy, Bostock Jennifer, Din Amy, Graham Cynthia A, Lewith George, Liossi Christina, O'Riordan Tim, White Peter, Yardley Lucy
Department of Psychology, University of Southampton, Southampton, United Kingdom.
Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.
J Med Internet Res. 2019 Jan 17;21(1):e9955. doi: 10.2196/jmir.9955.
Placebo effects and their underpinning mechanisms are increasingly well understood. However, this is poorly communicated to participants in placebo-controlled trials. For valid informed consent, participants should be informed about the potential benefits and risks of participating in placebo-controlled trials. Existing information leaflets often fail to describe the potential benefits and adverse effects associated with placebo allocation. This study tested the effects of a new website designed to inform patients about placebo effects (The Power of Placebos, PoP). PoP was designed using qualitative methods in combination with theory- and evidence-based approaches to ensure it was engaging, informative, and addressed patients' concerns.
This study aimed to test the effects of PoP, compared with a control website, on people's knowledge about placebo and the ability to make an informed choice about taking part in a placebo-controlled trial.
A total of 350 adults with back pain recruited from 26 general practices in Southern England participated in this Web-based study. Participants were randomly assigned to PoP (which presented scientifically accurate information about placebo effects in an engaging way) or a control website (based on existing information leaflets from UK trials). Participants self-completed Web-based pre- and postintervention questionnaire measures of knowledge about placebo effects and preintervention questionnaire measures of attitudes toward and intentions to participate in a placebo-controlled trial. The 2 primary outcomes were (1) knowledge and (2) informed choice to take part in a placebo-controlled trial (computed from knowledge, attitudes, and intentions).
After viewing PoP, participants had significantly greater knowledge about placebos (mean 8.28 [SD 1.76]; n=158) than participants who viewed the control (mean 5.60 [SD 2.24]; n=174; F=173.821; P<.001; η=.346). Participants who viewed PoP were 3.16 times more likely than those who viewed the control to make an informed choice about placebos (χ=36.5; P<.001).
In a sample of adults with back pain, PoP increased knowledge and rates of informed choice about placebos compared with a control website. PoP could be used to improve knowledge about placebo effects in back pain. After essential further development and testing in clinical trial settings, it could support informed consent in placebo-controlled trials.
安慰剂效应及其潜在机制已得到越来越深入的了解。然而，在安慰剂对照试验中，这一点却很少传达给参与者。为了获得有效的知情同意，应向参与者告知参与安慰剂对照试验的潜在益处和风险。现有的信息手册往往未能描述与安慰剂分配相关的潜在益处和不良反应。本研究测试了一个旨在向患者介绍安慰剂效应的新网站（安慰剂的力量，PoP）的效果。PoP采用定性方法并结合基于理论和证据的方法进行设计，以确保其具有吸引力、信息丰富且能解决患者的担忧。
本研究旨在测试与对照网站相比，PoP对人们关于安慰剂的知识以及对参与安慰剂对照试验做出明智选择的能力的影响。
从英格兰南部26家普通诊所招募了350名患有背痛的成年人参与这项基于网络的研究。参与者被随机分配到PoP组（以一种引人入胜的方式呈现关于安慰剂效应的科学准确信息）或对照网站组（基于英国试验现有的信息手册）。参与者自行完成基于网络的干预前和干预后关于安慰剂效应知识的问卷调查，以及干预前关于参与安慰剂对照试验的态度和意愿的问卷调查。两个主要结果是：（1）知识；（2）参与安慰剂对照试验的明智选择（根据知识、态度和意愿计算得出）。
观看PoP后，参与者对安慰剂的了解（平均8.28[标准差1.76]；n = 158）显著高于观看对照组的参与者（平均5.60[标准差2.24]；n = 174；F = 173.821；P <.001；η =.346）。观看PoP的参与者做出关于安慰剂明智选择的可能性是观看对照组参与者的3.16倍（χ = 36.5；P <.001）。
在患有背痛的成年人样本中，与对照网站相比，PoP增加了关于安慰剂的知识以及明智选择的比例。PoP可用于提高对背痛中安慰剂效应的认识。在临床试验环境中进行必要的进一步开发和测试后，它可支持安慰剂对照试验中的知情同意。
