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Placebo effect studies are susceptible to response bias and to other types of biases.
- Source :
-
Journal of clinical epidemiology [J Clin Epidemiol] 2011 Nov; Vol. 64 (11), pp. 1223-9. Date of Electronic Publication: 2011 Apr 23. - Publication Year :
- 2011
-
Abstract
- Objective: Investigations of the effect of placebo are often challenging to conduct and interpret. The history of placebo shows that assessment of its clinical significance has a real potential to be biased. We analyze and discuss typical types of bias in studies on placebo.<br />Study Design and Setting: A methodological analysis and discussion.<br />Results: The inherent nonblinded comparison between placebo and no-treatment is the best research design we have in estimating effects of placebo, both in a clinical and in an experimental setting, but the difference between placebo and no-treatment remains an approximate and fairly crude reflection of the true effect of placebo interventions. A main problem is response bias in trials with outcomes that are based on patients' reports. Other biases involve differential co-intervention and patient dropouts, publication bias, and outcome reporting bias. Furthermore, extrapolation of results to a clinical settings are challenging because of a lack of clear identification of the causal factors in many clinical trials, and the nonclinical setting and short duration of most laboratory experiments.<br />Conclusions: Creative experimental efforts are needed to assess rigorously the clinical significance of placebo interventions and investigate the component elements that may contribute to the therapeutic benefit.<br /> (Copyright © 2011 Elsevier Inc. All rights reserved.)
Details
- Language :
- English
- ISSN :
- 1878-5921
- Volume :
- 64
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- Journal of clinical epidemiology
- Publication Type :
- Academic Journal
- Accession number :
- 21524568
- Full Text :
- https://doi.org/10.1016/j.jclinepi.2011.01.008