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
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
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 (i.e., pre-trial 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 socio-demographic 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 six 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.
1-4
Hughes, John G.
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Greville-Harris, Madeleine L.
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Graham, Cynthia
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Lewith, George
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White, Peter
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Bishop, Felicity
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Hughes, John G.
285870fc-1a6a-437a-a13b-7ba0ae392413
Greville-Harris, Madeleine L.
15fdf3ab-d129-4191-bfd4-9c14c910bfef
Graham, Cynthia
ac400331-f231-4449-a69b-ec9a477224c8
Lewith, George
0fc483fa-f17b-47c5-94d9-5c15e65a7625
White, Peter
f33829fd-24c9-4b44-a148-24eca9d52253
Bishop, Felicity
1f5429c5-325f-4ac4-aae3-6ba85d079928
Hughes, John G., Greville-Harris, Madeleine L., Graham, Cynthia, Lewith, George, White, Peter and Bishop, Felicity
(2017)
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.
Journal of Medical Ethics, .
(doi:10.1136/medethics-2016-103964).
Abstract
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 (i.e., pre-trial 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 socio-demographic 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 six 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.
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Placebo misconceptions paper v25_complete
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medethics-2016-103964.full
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Accepted/In Press date: 14 May 2017
e-pub ahead of print date: 29 June 2017
Identifiers
Local EPrints ID: 412155
URI: http://eprints.soton.ac.uk/id/eprint/412155
ISSN: 1473-4257
PURE UUID: 258cdfdf-9f32-4307-b294-dd05865c34de
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Date deposited: 12 Jul 2017 16:30
Last modified: 21 Mar 2024 02:47
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Author:
John G. Hughes
Author:
Madeleine L. Greville-Harris
Author:
George Lewith
Author:
Peter White
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