The importance of placebo effects
Abstract
To the Editor. —The issue of bias was not raised in the otherwise excellent article by Dr Turner and colleagues1on placebo effects. The point is that the placebo arm of a trial is particularly vulnerable to specific types of bias. In clinical trials, as opposed to regular patient care, patients are generally highly compliant and have a good feeling about the trial because they think it will provide something from which they can benefit. They also do not want to disappoint the investigators who have taken so much interest in them. This wish not to disappoint may produce an enhanced placebo effect on the part of the participants. Investigators, on the other hand, may find it difficult or impossible to tell the complete truth about the dummy2and usually exaggerate the potential of the trial. Furthermore, many phase IV trials do not include a written informed consent
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The context surrounding treatment delivery can allow placebo effects to improve care benefits.
“There is an increasing body of literature suggesting that placebo effects can enhance the therapeutic benefits of care through the context in which the treatment is administered (Brody and Miller, 2011; Cleophas, 1995; de la Fuente-fernandex et al., 2002; Di Blasi et al., 2001; Finniss et al., 2010; Kaptchuk, 1998; Price et al., 2008; Thomas, 1994).”
From Distinct neural representations of placebo and nocebo effects (2015) · cites this paper as Cleophas, 1995
Cites
The Importance of Placebo Effects in Pain Treatment and Research
Turner, J. A. (1994) · JAMA · doi:10.1001/jama.1994.03510440069036 · Cited by 877 · see citing works
Crossover studies: A modified analysis with more power
Cleophas, T. J. (1993) · Clinical Pharmacology & Therapeutics · doi:10.1038/clpt.1993.64 · Cited by 30 · see citing works
Self-citationAvoiding the pitfalls of sponsored multicentre research in general practice.
Waldron, H. A., & Cookson, R. F. (1993) · BMJ · doi:10.1136/bmj.307.6915.1331 · Cited by 21 · see citing works
FUNDAMENTAL ISSUES OF CHOOSING THE RIGHT TYPE OF TRIAL
Cleophas, T. J., & Tavenier, P. (1994) · American Journal of Therapeutics · doi:10.1097/00045391-199412000-00013 · Cited by 20 · see citing works
Self-citationInformed consent in clinical trials. Should be comprehensive...
Emberton, M., Wood, C. A., & Meredith, P. (1993) · BMJ · doi:10.1136/bmj.307.6917.1494-b · Cited by 8 · see citing works
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Placebo effect studies are susceptible to response bias and to other types of biases
Hróbjartsson, A., Kaptchuk, T. J., & Miller, F. G. (2011) · Journal of Clinical Epidemiology · doi:10.1016/j.jclinepi.2011.01.008 · Cited by 150 · see citing works
Distinct neural representations of placebo and nocebo effects
Freeman, S., Yu, R., Egorova, N., Chen, X., Kirsch, I., Claggett, B., Kaptchuk, T. J., Gollub, R. L., & Kong, J. (2015) · NeuroImage · doi:10.1016/j.neuroimage.2015.03.015 · Cited by 116 · see citing works
“There is an increasing body of literature suggesting that placebo effects can enhance the therapeutic benefits of care through the context in which the treatment is administered (Brody and Miller, 2011; Cleophas, 1995; de la Fuente-fernandex et al., 2002; Di Blasi et al., 2001; Finniss et al., 2010; Kaptchuk, 1998; Pr…”
BackgroundPlacebo analgesia: findings from brain imaging studies and emerging hypotheses
Kong, J., Kaptchuk, T. J., Polich, G., Kirsch, I., & Gollub, R. L. (2007) · Reviews in the Neurosciences · doi:10.1515/revneuro.2007.18.3-4.173 · Cited by 97 · see citing works
- Authors
- Cleophas, T. J. M.
- Corresponding author
- Cleophas, Ton J. M.
- Venue
- JAMA: The Journal of the American Medical Association
- Publisher
- American Medical Association (AMA)
- Published
- 1995-01-25
- Volume
- 273
- Issue
- 4
- Pages
- 283
- ISSN
- 0002-9955 (ISSN-L)
- 0098-7484
- OpenAlex
- W2030943975
- Cited by
- 18
- References
- 5
- Citations by year
- 2025: 1 · 2023: 1 · 2015: 1 · 2014: 1
- FWCI
- 0.85
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- JAMA (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Life Sciences › Neuroscience › Cognitive Neuroscience › Pain Management and Placebo Effect
- Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
- Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Ethics in Clinical Research
- Keywords
- placebo effect, bias in clinical trials, placebo arm, medication adherence, investigator bias, informed consent
- MeSH terms
- Clinical Trials as Topic, Humans, Placebos
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