Abstract
Background: 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. Objective: 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. Methods: 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). Results: 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; F1,329=173.821; P
| Original language | English |
|---|---|
| Article number | e9955 |
| Number of pages | 15 |
| Journal | JMIR |
| Volume | 21 |
| Issue number | 1 |
| Early online date | 17 Jan 2019 |
| DOIs | |
| Publication status | Published - 17 Jan 2019 |
Research Groups and Themes
- Physical and Mental Health
- Digital Health
Keywords
- placebos
- placebo effects
- informed consent
- research ethics
- health knowledge, attitudes, practice
- internet
Access to Document
- Full-text PDF (final published version)
This is the final published version of the article (version of record). It first appeared online via JIMR Publications at https://www.jmir.org/2019/1/e9955/. Please refer to any applicable terms of use of the publisher.