School of Health Sciences, University of South Australia, Adelaide, SA, Australia.
Clin Trials. 2020 Jun;17(3):295-305. doi: 10.1177/1740774520910365. Epub 2020 Mar 10.
BACKGROUND/AIMS: In clinical trials of physical interventions, participant blinding is often poorly addressed and therapist blinding routinely omitted. This situation presents a substantial barrier to moving the field forward. Improving the success of blinding will be a vital step towards determining the true mechanisms of physical interventions. We used a Delphi approach to identify important elements of shams for physical interventions to maximise the likelihood of participant and therapist blinding in clinical trials.
Two expert groups were recruited: (1) experts in research methodology and (2) experts in deceptive and/or hypnotic techniques including magic. Magicians were included because they were considered a potentially rich source of innovation for developing credible shams due to their unique skills in altering perceptions and beliefs. Three rounds of survey were conducted, commencing with an open-ended question. Responses were converted to single 'items', which participants rated in the following two rounds using a 9-point Likert scale, categorised as 'Not important' (0-3), 'Depends' (4-6) and 'Essential' (7-9). Consensus was pre-defined as ≥80% agreement within a 3-point category.
Thirty-eight experts agreed to participate (research methodology: = 22; deceptive and/or hypnotic techniques: = 16), and 30 experts responded to at least one round (research methodology: = 19; deceptive and/or hypnotic techniques: = 11). Of 79 items, five reached consensus in the 'Essential' category in both groups, which related to beliefs of participants ( = 3 items), interactions with researchers ( = 1 item) and standardisation of clinical assessments ( = 1 item). Thirteen additional items reached consensus in the 'Essential' category in one group. Experts in research methodology had one additional item reach consensus, related to authentic delivery of study information. The remaining 12 additional items that reached consensus in the deceptive and/or hypnotic techniques group related mainly to therapist attitude and behaviour and the clinical interaction.
Experts agreed that, for shams to be believable, consideration of cognitive influences is essential. Contrary to the focus of previous shams for physical interventions, replicating the tactile sensation of the active treatment was not considered an essential part of sham development. Therefore, when designing sham-controlled clinical trials, researchers should carefully consider the cognitive credibility of the entire intervention experience, and not just the indistinguishability of the sham intervention itself. The findings provide new guidance to researchers on important contributors to blinding in physical intervention trials.
背景/目的：在物理干预的临床试验中，参与者的盲法通常处理不当，治疗师的盲法也经常被忽略。这种情况对推动该领域的发展构成了重大障碍。提高盲法的成功率将是确定物理干预真实机制的重要一步。我们使用德尔菲法来确定物理干预的假治疗的重要元素，以最大限度地提高临床试验中参与者和治疗师的盲法可能性。
招募了两个专家组：（1）研究方法专家，（2）欺骗和/或催眠技术专家，包括魔术。之所以选择魔术师，是因为他们由于独特的改变感知和信念的技能，被认为是开发可信假治疗的潜在创新来源。进行了三轮调查，从一个开放式问题开始。答复被转换为单个“项目”，参与者在以下两轮中使用 9 分李克特量表进行评分，分为“不重要”（0-3）、“取决于”（4-6）和“必要”（7-9）。共识定义为在 3 分类别内达成≥80%的一致。
38 名专家同意参与（研究方法：=22；欺骗和/或催眠技术：=16），至少有 30 名专家回复了至少一轮（研究方法：=19；欺骗和/或催眠技术：=11）。在 79 个项目中，有 5 个在两个组的“必要”类别中达成共识，这些项目涉及参与者的信念（=3 个项目）、与研究人员的互动（=1 个项目）和临床评估的标准化（=1 个项目）。在一个组中，还有 13 个额外的项目在“必要”类别中达成共识。研究方法专家的一项额外项目也达成了共识，与研究信息的真实传递有关。在欺骗和/或催眠技术组中达成共识的其余 12 个额外项目主要涉及治疗师的态度和行为以及临床互动。
专家们一致认为，为了使假治疗具有可信度，必须考虑认知影响。与之前物理干预假治疗的重点不同，复制主动治疗的触觉感觉不被认为是假治疗发展的必要部分。因此，在设计假对照临床试验时，研究人员应仔细考虑整个干预体验的认知可信度，而不仅仅是假干预本身的不可区分性。研究结果为物理干预试验中的盲法提供了新的指导，强调了重要的贡献因素。
