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Describing placebos in patient information leaflets: effects on patients’ beliefs

Describing placebos in patient information leaflets: effects on patients’ beliefs
Describing placebos in patient information leaflets: effects on patients’ beliefs
Background

There are ethical shortcomings to current standard practices regarding the provision of information about placebos in clinical trials. Written information about placebos for clinical trial participants can be incomplete and even misleading. We aimed to develop accurate yet accessible written information about placebos for patients who might participate in clinical trials, and to test the effects of such information on patients’ beliefs about placebos.

Methods

With input from 22 patients and public volunteers, a new, “elaborated” information leaflet was developed to provide accessible and evidence-based information about placebos and their possible effects. A “standard” leaflet was also produced which gave a neutral but incomplete description of placebos. In an online experiment 328 participants with chronic health conditions were randomised to read either the elaborated or the standard leaflet. Participants completed validated measures of the credibility and expected effectiveness of placebo treatment for pain and intentions, attitudes, perceived behavioural control, and subjective norms towards taking part in a placebo-controlled trial.

Results

The elaborated leaflet had a significant positive effect on participants’ ratings of the credibility (t(326)=-2.78, p<.01) and effectiveness (t(326)=-2.59, p<.05) of placebo treatment for pain. It had no effect on intentions to take part in placebo-controlled clinical trials.

Conclusions

The elaborated leaflet provided more comprehensive information about placebos than is commonly provided in current clinical trials. Such a leaflet appears to have greater ethical validity and might increase the magnitude of placebo effects. Further research is needed with participants who are actively considering enrolling in a placebo-controlled trial.
2052-5648
609-617
Bishop, F.L.
1f5429c5-325f-4ac4-aae3-6ba85d079928
McGinn, L.
e326847e-01d4-4f7b-a3a9-8879d2db718e
Graham, C.A.
ac400331-f231-4449-a69b-ec9a477224c8
Biggs, H.
d0d08de6-6cae-4679-964c-eac653d7722b
Denegri, S.
f9aa94d0-595e-43b7-82cb-f4a5fe962c5e
Lewith, G.T.
0fc483fa-f17b-47c5-94d9-5c15e65a7625
Bishop, F.L.
1f5429c5-325f-4ac4-aae3-6ba85d079928
McGinn, L.
e326847e-01d4-4f7b-a3a9-8879d2db718e
Graham, C.A.
ac400331-f231-4449-a69b-ec9a477224c8
Biggs, H.
d0d08de6-6cae-4679-964c-eac653d7722b
Denegri, S.
f9aa94d0-595e-43b7-82cb-f4a5fe962c5e
Lewith, G.T.
0fc483fa-f17b-47c5-94d9-5c15e65a7625

Bishop, F.L., McGinn, L., Graham, C.A., Biggs, H., Denegri, S. and Lewith, G.T. (2016) Describing placebos in patient information leaflets: effects on patients’ beliefs. European Journal for Person Centered Healthcare, 4 (4), 609-617. (doi:10.5750/ejpch.v4i4.1145).

Record type: Article

Abstract

Background

There are ethical shortcomings to current standard practices regarding the provision of information about placebos in clinical trials. Written information about placebos for clinical trial participants can be incomplete and even misleading. We aimed to develop accurate yet accessible written information about placebos for patients who might participate in clinical trials, and to test the effects of such information on patients’ beliefs about placebos.

Methods

With input from 22 patients and public volunteers, a new, “elaborated” information leaflet was developed to provide accessible and evidence-based information about placebos and their possible effects. A “standard” leaflet was also produced which gave a neutral but incomplete description of placebos. In an online experiment 328 participants with chronic health conditions were randomised to read either the elaborated or the standard leaflet. Participants completed validated measures of the credibility and expected effectiveness of placebo treatment for pain and intentions, attitudes, perceived behavioural control, and subjective norms towards taking part in a placebo-controlled trial.

Results

The elaborated leaflet had a significant positive effect on participants’ ratings of the credibility (t(326)=-2.78, p<.01) and effectiveness (t(326)=-2.59, p<.05) of placebo treatment for pain. It had no effect on intentions to take part in placebo-controlled clinical trials.

Conclusions

The elaborated leaflet provided more comprehensive information about placebos than is commonly provided in current clinical trials. Such a leaflet appears to have greater ethical validity and might increase the magnitude of placebo effects. Further research is needed with participants who are actively considering enrolling in a placebo-controlled trial.

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Informing patients about placebo effects EJPCH.docx - Accepted Manuscript
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More information

Accepted/In Press date: 17 June 2016
Published date: 15 December 2016
Organisations: Southampton Law School

Identifiers

Local EPrints ID: 391096
URI: http://eprints.soton.ac.uk/id/eprint/391096
ISSN: 2052-5648
PURE UUID: bbd461ea-20e7-4b27-866a-cfc65d3559f3
ORCID for F.L. Bishop: ORCID iD orcid.org/0000-0002-8737-6662
ORCID for C.A. Graham: ORCID iD orcid.org/0000-0002-7884-599X
ORCID for H. Biggs: ORCID iD orcid.org/0000-0002-4434-6543

Catalogue record

Date deposited: 08 Apr 2016 09:20
Last modified: 16 Jul 2020 00:32

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