RT Journal Article
SR Electronic
T1 What trial participants need to be told about placebo effects to give informed consent: a survey to establish existing knowledge among patients with back pain
JF Journal of Medical Ethics
JO J Med Ethics
FD BMJ Publishing Group Ltd and Institute of Medical Ethics
SP medethics-2016-103964
DO 10.1136/medethics-2016-103964
A1 John Hughes
A1 Maddy Greville-Harris
A1 Cynthia A Graham
A1 George Lewith
A1 Peter White
A1 Felicity L Bishop
YR 2017
UL http://jme.bmj.com/content/early/2017/06/29/medethics-2016-103964.abstract
AB Introduction Patients require an accurate knowledge about placebos and their possible effects to ensure consent for placebo-controlled clinical trials is adequately informed. However, few previous studies have explored patients’ baseline (ie, pretrial recruitment) levels of understanding and knowledge about placebos. The present online survey aimed to assess knowledge about placebos among patients with a history of back pain.Design A 15-item questionnaire was constructed to measure knowledge about placebos. Additional questions assessed sociodemographic characteristics, duration and severity of back pain, and previous experience of receiving placebos.Setting Participants recruited from community settings completed the study online.Results 210 participants completed the questionnaire. 86.7% had back pain in the past 6 months, 44.3% currently had back pain. 4.3% had received a placebo intervention as part of a clinical trial and 68.1% had previously read or heard information about placebos. Overall knowledge of placebos was high, with participants on average answering 12.07 of 15 questions about placebos correctly (SD=2.35). However, few participants correctly answered questions about the nocebo effect (31.9% correct) and the impact of the colour of a placebo pill (55.2% correct).Conclusions The findings identified key gaps in knowledge about placebos. The lack of understanding of the nocebo effect in particular has implications for the informed consent of trial participants. Research ethics committees and investigators should prioritise amending informed consent procedures to incorporate the fact that participants in the placebo arm might experience adverse side effects.